Answer:
first law: an object remains in uniform motion except an external force has acted upon it eg a ball in stable motion doesn't move until one moves or kicks it
second law:the body acted upon by an external force gains a momentum which is directly proportional to the applied force and acts in the direction of the force
third law: to every action there is an equal and opposite reaction eg if u push someone the person moves backward away from you and not towards you
Answer:
Newton's Second law of motion: "Force = mass × acceleration."
Newton's Third law of motion: "Every action has an equal and opposite reaction."
Explanation:
An example of Newton's third law is when a rocket is launched, the boosters apply force on the ground and the ground pushes back, which makes the rocket take off.
Why do physicists say mass is more fundamental than weight??
Answer:
because mass of a matter never changes
on the other hand the weight of a matter changes due to gravity
for example the
on the moon the pull of gravity is less than it is on earth so the Weight of an object will be less on the moon but the mass of it will stay the same
Explanation:
I
Mass is more fundamental than weight because mass is a consistent measure of the quantity of matter, whereas weight is the gravity-dependent force acting on an object and can vary. The confusion between these terms occurs often in everyday language, especially since they are used interchangeably.
Physicists say that mass is more fundamental than weight because mass is an intrinsic property of an object that represents the quantity of matter, which does not vary in classical physics. Conversely, weight is the gravitational force acting on an object, which can vary depending on the location and gravity. Therefore, mass is a more consistent and universal characteristic of matter than weight, which can differ even on Earth depending on elevation or geographic location.
The confusion between mass and weight arises as the terms are used interchangeably in everyday language. For instance, our medical records may show our weight in kilograms, which is actually a unit of mass, instead of the correct unit of newtons, which is used to measure gravitational force. This interchangeability of terms has led to a common misunderstanding of these distinct physical quantities.
The relationship between mass and weight becomes particularly evident in space.
what is resistance? Difference between resistance and resistivity.
Answer:
Resistance is the opposition that a substance offers to the flow of electric current
Explanation:
resistance is the opposition and Resistivity is a measure of the resistance of a given size of a specific material to electrical conduction.
Final answer:
Resistance is the opposition to electric current flow in materials, measured in ohms, while resistivity is a fundamental property of the material itself, indicating how much it resists electric current flow.
Explanation:
Understanding Resistance and Resistivity in Physics
Resistance is a measure of the difficulty in passing an electric current through a wire or component. It has units of ohms and is calculated by the formula V = IR, where V is voltage, I is current, and R is resistance. Resistivity, represented by the symbol p, is a material property that quantifies how strongly a material opposes the flow of electric current. The resistance R of a cylindrical object like a wire can be calculated using the formula R = pL/A, where L is the length and A is the cross-sectional area.
The key difference between resistance and resistivity is that resistivity is an intrinsic property of a material, which means it does not change regardless of the shape or size of the material. In contrast, resistance is an extrinsic property that depends on both the material's resistivity and the physical dimensions of the object. Materials can generally be categorized into conductors, semiconductors, and insulators, based on their resistivity values.
This graph describes the motion of a sky diver that jumped from an airplane. The skydiver is MOST LIKELY ?
A) being influenced by equal amounts of gravity and air resistance.
B) slowing down because of an unbalanced force of air resistance.
C) accelerating because of an unbalanced force of gravity.
Eliminate
D) on the ground and is not falling anymore.
Answer:
A) being influenced by equal amounts of gravity and air resistance.
Explanation:
B) slowing down because of an unbalanced force of air resistance.
False - if it was slowing down, then the velocity would go down.
D) on the ground and is not falling anymore.
False - This would be mistaken as the answer but it is not because if the person is not falling anymore the horizontal line should be at the x-axis, meaning that there is no more velocity.
C) accelerating because of an unbalanced force of gravity.
False - The line would otherwise be going up or down.
The shape of the graph of the magnitude of the acceleration versus time for a falling skydiver initially increases and then decreases towards zero as the skydiver reaches terminal velocity. The graph of the magnitude of the velocity versus time initially increases and then reaches a plateau at terminal velocity. The graph of the magnitude of the displacement versus time initially increases and then levels off as the skydiver experiences constant displacement.
Explanation:In the case of a skydiver, the shape of the graph of the magnitude of the acceleration versus time will initially be positive and then decrease towards zero as the skydiver reaches terminal velocity. This is because the skydiver is initially accelerating due to the unbalanced force of gravity, but as they approach terminal velocity, the force of air resistance opposes the force of gravity and causes the acceleration to decrease.
Similarly, the shape of the graph of the magnitude of the velocity versus time for a falling skydiver will initially be positive and then reach a plateau at terminal velocity.
Lastly, the shape of the graph of the magnitude of the displacement versus time for a falling skydiver will initially be positive and then level off as the skydiver reaches terminal velocity and experiences constant displacement.
a 2-kg bowling ball is 2.5 meters off the ground on a post when it falls. Just before it reaches the ground, it is traveling 7 m/s. Assuming tht there is no air resistance, which statement is true? 1. the initial potential energy is greater than the final kinetic energy 2. the mechanical energy is conserved 3. the mechanical energy is not conserved 4. the initial potential energy is less than the final kinetic energy
“The mechanical energy is conserved" in the given system is true out of all given options.
Answer: Option 2
Explanation:
According to law of conservation of energy, the energy will neither be created nor be destroyed, irrespective of the type of energy. As in the present case, the ball is bowled and it is travelling to ground, so the mechanical energy is working in this case. Thus the mechanical energy will be conserved. Even it can be shown as follows.
As the 2 kg ball is travelling with a speed of 7 m/s, the kinetic energy exhibited by the ball while falling to ground will be
[tex]\text {Kinetic energy}=\frac{1}{2} \times \text { mass of the ball } \times\left(\text { speed of the ball) }^{2}\right.[/tex]
Thus, applying given values, we get,
[tex]\text {Kinetic energy exhibited by the ball}=\frac{1}{2} \times 2 \times 7 \times 7=49 \mathrm{J}[/tex]
Similarly, as the ball is 2.5 m above ground, the potential energy will also be exhibited by the ball at that position. So the potential energy will be
[tex]\text {Potential energy}=\text {Mass} \times \text {acceleration} \times \text {height}[/tex]
Thus,
[tex]\text { Potential energy exhibited by the ball }=2 \times 9.8 \times 2.5=49 \mathrm{J}[/tex]
Thus as the magnitude of kinetic energy is equal to the magnitude of potential energy exhibited by the ball with varying direction, the net energy will be zero. This is because the kinetic energy will be acting in opposite direction to the potential energy exhibited by the ball. Hence as the net energy is zero, the mechanical energy is conserved.
A uniforn half metre rule is pivated at its 30cm mark. A mass of 50g hung at the 45cm mark keeps the rule horizontal. determine the mass of the half metre rule
150 g
Explanation:From the question;
Half meter rule (50 cm) is pivoted at 30 cm Mass of 50 g Pivoted at 45 cmIt means the mass is 15 cm from the pivot
Mass of the meter rule is always at the center of the rule ( 25 cm mark)Therefore, the mass of the half meter rule is experienced 5 cm from the pivot.But, According to law of moments, clockwise moments is equal to anticlockwise moments when a system is at a state of balance.Therefore;
Assuming the mass of half meter rule is m
Then;
m × 5 cm = 50 g × 15 cm
m = 150 g
Therefore;
Mass of the half meter rule is 150 g
The mass of the half meter ruler is 150g
Pus is a mixture of dead neutrophils, dead tissue, bacteria, and living white blood cells.
A.
True
B.
False
Final answer:
The statement is true, as pus is composed of dead neutrophils, dead tissue, bacteria, and living white blood cells. It reflects the immune system's response to infection, with pus indicating an accumulation of these elements at the site of infection.
Explanation:
The statement "Pus is a mixture of dead neutrophils, dead tissue, bacteria, and living white blood cells" is true. Pus is indeed an accumulation of these components. When neutrophils, which are a type of leukocyte, respond to an infection, they engulf pathogens in a process called phagocytosis. The dead neutrophils, along with any other cellular debris, dead pathogens, and living immune cells, such as macrophages still fighting the infection, aggregate to form pus at the infection site.
This purulent or suppurative discharge is a typical sign of the body's defensive responses engaging with the invading microorganisms. While small amounts of pus can indicate a healthy immune response, in history, there were attempts to produce pus artificially under the misguided notion that it could aid in healing. We now know that inducing pus does not promote recovery and that a natural immune response is best in fighting infections.
Two plane mirrors are facing each other. They are parallel, 5.00 cm apart, and 30.0 cm in length, as the drawing indicates. A laser beam is directed at the top mirror from the left edge of the bottom mirror. What is the smallest angle of incidence with respect to the top mirror, such that the laser beam hits each mirror only twice.
Answer:
The minimum angle of incidence is, ∅ = 56° 18' 35'' to the normal
Explanation:
Given data,
The distance between the two plane mirror, d = 5 cm
The length of the plane mirror, L = 30 cm
According to the laws of reflection, the angle of incidence is equal to the angle of reflection.
If the laser beam touches each mirror only twice, then the base of the triangle formed is not less than L/2.
Let ∅ be the angle of incidence to the normal. The normal divides the triangle into two equal halves where base becomes L/4.
Therefore,
tan ∅ = opp / adj
= (L/4) / d
= (30/4) / 5
tan ∅ = 1.5
∅ = tan ⁻¹ (1.5)
= 56° 18' 35''
Hence, the minimum angle of incidence is, ∅ = 56° 18' 35'' to the normal.
Mr.G I running down the street trying to catch the bus. He is one city block away (200m) and this bus is leaving in 10s.
a) How fast does Mr.G need to run to catch the bus on time? (Hint: what do you know about the problem)
b) If the fastest human can run 12 m/s, will Mr.G be able to catch the bus? Explain your answer
Answer:
a) 20 m/s
b) No
Explanation:
a)
Mr. G needs to run x= 200 m in t = 10 seconds to catch the bus.
Knowing the speed is computed as
[tex]\displaystyle v=\frac{x}{t}[/tex]
We have
[tex]\displaystyle v=\frac{200m}{10s}=20m/s[/tex]
b)
The fastest human can run 12 m/s, so Mr. G won't be able to catch the bus because he needs to run faster than that
Final answer:
Mr.G needs to run at 20 meters per second to catch the bus, but since the fastest human can run only at 12 meters per second, it is impossible for Mr.G to catch the bus on time.
Explanation:
To solve for how fast Mr.G needs to run to catch the bus on time, we need to find his required speed. Speed is calculated by dividing the distance by the time. Since Mr.G is 200 meters away from the bus and he has 10 seconds to reach it, his required speed is 20 meters per second (200m / 10s = 20m/s).
Regarding whether Mr.G can catch the bus, considering the fastest human can run at a speed of 12 meters per second, it is unfortunately impossible for Mr.G to catch the bus. The required speed to catch the bus is 20m/s, which exceeds the maximum human running speed.
if 2.0 J of work is done in raising a 180 g apple, how far is it lifted
Answer:
1.14 meters
Explanation:
You have already learned that work and energy have same units i.e. Joule (J).
If the object has travelled some distance (upwards) then there must be some potential difference (increased potential energy).
Thus the energy needed to lift the ball can be found by this formula:
E
p
=
m
⋅
g
⋅
h
Where
E
p
means potential energy needed (or simply work done). m stands for mass, g for gravitational energy, and h for the height reached.
Now we know the energy(2 J), the mass (0.18 kg), and gravitational energy (9.8 m/s^2). Putting into the formula we get:
2
=
0.18
⋅
9.8
⋅
h
2
0.18
⋅
9.8
=
h
2
1.76
=
h
1.14
=
h
Finally,
height reached above the ground = 1.14 m
How is a gas affected when pressure, temperature, or volume
change?
Explanation:
I never really took physics yet, but I do have some general knowledge of particle physics.
When pressure increases, the gas molecules will get closer together and rise in temperature, vice versa. (That's actually one way we get energy. The more pressure we apply to gas, the hotter it gets and therefore releases pretty good amounts of energy)
When temperature increases, the gas molecules will try to get away from each other and spread out, vice versa. The higher the temperature, the faster the particles move
And when volume increase, there is more room for the gas particles to bounce around and they are generally spread out from each other.
Someone else can answer if I didn't explain it correctly
Answer:
The volume of a given gas sample is directly proportional to its absolute temperature at constant pressure (Charles's law). The volume of a given amount of gas is inversely proportional to its pressure when temperature is held constant (Boyle's law).
Explanation:
A golfer takes two putts to sink his ball in the hole. The first putt displaces the ball 6.50 m east, and the second putt displaces it 5.90 m south. What displacement would put the ball in the hole in one putt?
Explanation:
Let east represent X axis and north represent Y axis.
We need to find what displacement would put the ball in the hole in one putt.
The first putt displaces the ball 6.50 m east
First displacement = 6.50 i m
The second putt displaces it 5.90 m south
Second displacement = -5.90 j m
Total displacement = 6.50 i - 5.90 j
[tex]\texttt{Magnitude = }\sqrt{6.50^2+(-5.90)^2}=8.78m\\\\\texttt{Direction = }tan^{-1}\left ( \frac{-5.9}{6.5}\right )=-42.23^0[/tex]
So displacement to hole from initial position is 8.78 m at direction 42.23° south of east.
Starting from rest, a 75.0-kg snowboarder slides straight down a 115-m slope in 6.6 s. If the slope is a 35°
incline, find the following:
(a) The acceleration of the snowboarder.
The acceleration of the snowboarder is [tex]5.6 m/s^2[/tex] down along the incline
Explanation:
To find the acceleration of the snowboard, we have to analyze the forces acting along the direction parallel to the incline.
There is only one force acting in this direction, and it is the component of the weight parallel to the incline, given by
[tex]mg sin \theta[/tex]
where
m = 75.0 kg is the mass of the man
[tex]g=9.8 m/s^2[/tex] is the acceleration of gravity
[tex]\theta=35^{\circ}[/tex] is the angle of the incline
Substituting, we find that the net force along the incline is:
[tex]F=(75.0)(9.8)(sin 35^{\circ})=421.6 N[/tex]
According to Newton's second law, the net force on the snowboard is equal to the product between his mass and his acceleration:
[tex]F=ma[/tex]
where a is the acceleration. Therefore, solving for a, we find
[tex]a=\frac{F}{m}=\frac{421.6}{75}=5.6 m/s^2[/tex]
And the direction of this acceleration is down along the incline.
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A group of researchers is studying the effects of stress on decision making. They provide a group of candidates with questionnaire to fill
out and place them in mildly stressful situations. The following table shows the time taken to complete the questionnaire what is the
mean and median of the sample data?
subject 1 120 seconds
subject 2 139 seconds
subject 3 103 seconds
subject 4 100 seconds
subject 5 112 seconds
The median of the samples
The mean of the sample set is. ____________. The median of the sample set is ____________.
Answer:
Mean: 114.8
Median: 112
Explanation:
The mean is the average of the numbers so you add them all together and divide by the number of terms. The median is the middle value when the terms are in order from least to greatest.
Answer:
Mean of the sample set = 114.8
Median of the sample set = 112
Explanation:
To calculate mean, add value of all samples and then divide with number of samples.
Mean of the sample set = (100+103+112+120+139)/5 = 114.8
To calculated median, arrange the values in ascending order then take the value which is at middle.
100, 103, 112, 120, 139
“112” is at the middle so,
Median of the sample set = 112
A motorcycle begins at rest and accelerates uniformly S7.9 we want to find a time to take the motorcycle to reach a speed of 100 which chimeric formula would be most useful to solve for the target unknown
The motorbike reaches 100 km/h in 3.5 seconds
Explanation:
The motion of the motorbike is a uniformly accelerated motion (= constant acceleration), therefore we can use the following suvat equation:
[tex]v=u+at[/tex]
where
v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
For the motorbike in this problem,
u = 0 (it starts from rest)
[tex]v = 100 km/h = 27.8 m/s[/tex] is the final velocity
[tex]a=7.9 m/s^2[/tex] is the acceleration
Solving for t, we find the time it takes for the bike to reach that velocity:
[tex]t=\frac{v-u}{a}=\frac{27.8-0}{7.9}=3.5 s[/tex]
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why is "Galloping Gertie" an appropriate nickname for the bridge
Answer:
"Galloping Gertie" is an appropriate nickname for the bridge Tacoma Narrows.
Explanation:
The Tacoma Narrows Bridge is slender, elegent and graceful bridge is stretched like a steel ribbon across Puget Sound in 1940.
When Galloping Gertie splashed into Puget Sound, it created ripple effects across the nation and around the world. The event changed forever how engineers design suspension bridges.
Tacoma Narrows Bridge The original bridge received its nickname "Galloping Gertie" because of the vertical movement of the deck observed by construction workers during windy conditions.
Final answer:
The nickname 'Galloping Gertie' is appropriate for the bridge because it refers to the Tacoma Narrows Bridge, which famously collapsed due to strong winds.
Explanation:
The nickname 'Galloping Gertie' is appropriate for the bridge because it refers to the Tacoma Narrows Bridge, which famously collapsed due to strong winds. When the bridge experienced wind-induced vibrations, it appeared to be galloping like a horse, hence the nickname. The collapse of Galloping Gertie serves as an important lesson in engineering and the need for understanding the effects of forces on structures.
Different measurements are expressed in different units. Choose the correct SI units for the following types of
measurement
The SI units for measuring the velocity of the car:
The SI units for measuring the acceleration of the car:
The SI units for measuring force:
The SI units for measuring mass:
Answer: I don't know why people just cant give a straight answer.
Meters per second
Meters per second Squared
Newtons
Kilograms
100% right keep it going.
Explanation:
The S.I. units for measuring the velocity, acceleration, force, and mass are meter per second (m/s), meter per second squared (m/s²), Newton (N), and Kilogram (Kg) respectively.
What is the International System of Units?The International System of Units or S.I. units can be described as the modern version of the metric system and the world's most globally used system of measurement which is established and controlled by the Conference on Weights and Measures.
S.I. units system can be described as a system of measurement used in every country in the world employed in technology, industry, science, and commerce.
The S.I. exhibits a coherent system of units starting with seven base units. The second (s, the unit of time), Kilogram (kg, unit of mass), meter (m, length), kelvin (K, unit of temperature), mole (mol, amount of substance), ampere (A, unit of electric current), and candela (cd, luminous intensity).
Velocity is the ratio of distance and time so it has an S.I. unit of meter per second. Acceleration is the ratio of velocity and time so it has an S.I. unit of meter per second squared.
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I am driving 65 mph when I suddenly come to a stop. my acceleration was -9.2 m/s squared. how long did it take me to stop?
hint: convert mph to m/s first
The car takes 3.15 s to stop
Explanation:
The motion of the car is a uniformly accelerated motion (=constant acceleration), therefore we can use the following suvat equation:
[tex]v=u+at[/tex]
where
v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
Keeping in mind that
1 mile = 1609 metres
1 hour = 3600 seconds
Here we have:
[tex]u = 65 mph \cdot \frac{1609 m/mile}{3600 s/hour}=29.0 m/s[/tex] is the initial velocity, converted into m/s
v = 0 is the final velocity (the car comes to a stop)
[tex]a=-9.2 m/s^2[/tex] is the acceleration
And solving the equation for t, we find
[tex]t=\frac{v-u}{a}=\frac{0-29.0}{-9.2}=3.15 s[/tex]
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Which of the following is the best thermal insulator?
A.) Air
B.) Water
C.) Metal
D.) Stone
Please help I’m torn between A and B. I’ve asked many and people say A, but I asked my science teacher and she said B. And also I’ve researched and on answers.com also says Water is the better insulator..but idk I’m conflicted! APEX
Answer:
It's actually air
Explanation:
The best thermal insulator will be A) Air
What is thermal insulator ?Thermal insulator is the process of insulating against transmission of heat .
Air is the best thermal insulator if the distance between the molecule is greater because air has gaseous state , it is even harder for the heat to transfer through the material . Air is good insulator because its spread out molecular structure resists heat transfer .
correct option is a) Air
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what percentage of the earth's surface is covered in water
Answer:
71 % of the earth's surface is covered in water
Answer:
71%
Explanation:
How much heat is lost when 10 g of Glass cools 15 Celsius
The heat lost by the glass is 126 J
Explanation:
The amount of heat lost by a substance is proportional to the change in temperature of the substance according to the following equation:
[tex]Q=mC_s \Delta T[/tex]
where
Q is the amount of heat lost
m is the mass of the substance
[tex]C_s[/tex] is the specific heat capacity of the substance
[tex]\Delta T[/tex] is the change in temperature
In this problem, we have:
m = 10.0 g is the mass of the glass
[tex]\Delta T = -15^{\circ}C[/tex] is the change in temperature of the glass
[tex]C_s = 0.840 J/g{\circ}C[/tex] is the specific heat capacity of glass
Substituting and solving for Q, we find
[tex]Q=(10)(0.840)(-15)=-126 J[/tex]
So, the heat lost by the glass is 126 J.
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The heat loss for 10 g cooling by 15 °C can be calculated; the result would be -126 J.
To find out how much heat is lost when 10 g of glass cools by 15 °C, one would need to know the specific heat capacity of glass and use the formula: Q = mcΔT, where 'Q' is the quantity of heat, 'm' is the mass, 'c' is the specific heat capacity, and 'ΔT' is the change in temperature. Unfortunately, the specific heat capacity of glass is not provided in the question or the examples, which is necessary to calculate the exact amount of heat lost. However, for illustration, if we assume a typical value for glass is approximately 0.84 J/g°C, the calculation for the heat lost would be: Q = 10 g × 0.84 J/g°C × (-15 °C) = -126 J (negative sign indicating loss).
Un cuerpo se mueve a la derecha sobre una superficie horizontal áspera a una velocidad constante bajo la acción de una fuerza horizontal de 15 N. Determine:
a) Modulo y dirección de la fuerza de roce
Answer:
Fuerza de roce = 15 N
Hacia la izquierda
Explanation:
Las leyes de Newton explican el comportamiento de cuerpos bajo efectos de fuerzas externas. La primera ley especifica que un cuerpo no cambiará su estado de movimiento mientras una fuerza desequilibrante no lo acelere. Es decir, un cuerpo que se mueve a velocidad constante, tiene cero fuerza desequilibrante.
Como el cuerpo se está moviendo a velocidad constante, no hay aceleración y por lo tanto la fuerza total es cero.
Dado que estamos aplicando una fuerza horizontal de 15N y aún así el cuerpo se mueve a velocidad constante, significa que esa fuerza está siendo contrarrestada por la fuerza de roce hasta producir un equilibro de fuerzas y por lo tanto, cero fuerza desequilibrante.
La fuerza de roce es entonces, en módulo igual a la fuerza aplicada, es decir, 15 N
Su dirección siempre es opuesta al movimiento, así que la fuerza de roce se dirige hacia la izquierda
Think Critically Predict what would happen to the volume of a gas
if the pressure on that gas were doubled and then the absolute
temperature of the gas were doubled.
The volume of the gas does not change
Explanation:
To solve this problem, we can apply the ideal gas equation, which states that:
[tex]\frac{pV}{T}=const.[/tex]
where
p is the pressure of the gas
V is its volume
T is its absolute temperature
The equation can also be written as
[tex]\frac{p_1 V_1}{T_1}=\frac{p_2 V_2}{T_2}[/tex]
where in this problem we have:
[tex]p_1[/tex] is the initial pressure of the gas
[tex]V_1[/tex] is the initial volume
[tex]T_1[/tex] is the initial temperature
[tex]p_2 = 2 p_1[/tex] is the final pressure (twice the initial pressure)
[tex]V_2[/tex] is the final volume
[tex]T_2 = 2T_1[/tex] is the final temperature (twice the initial temperature)
Solving for V2, we find what happens to the volume of the gas:
[tex]V_2 = \frac{p_1 V_1 T_2}{p_2 T_1}=\frac{p_1 V_1 (2T_1)}{(2p_1) T_1}=V_1[/tex]
Therefore, the volume of the gas does not change.
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A 2.0 kg block is pushed 1.0 m at a constant
velocity up a vertical wall by a constant force
applied at an angle of 27.0
◦ with the horizontal, as shown in the figure.
The acceleration of gravity is 9.81 m/s
2.
If the coefficient of kinetic friction between
the block and the wall is 0.40, find
a) the work done by the force on the block.
Answer in units of J.
b) the work done by gravity on the block.
Answer in units of J.
c) the magnitude of the normal force between
the block and the wall.
Answer in units of N.
1) Work done by the force: 8.3 J
2) Work done by gravity: -19.6 J
3) Normal force: 16.3 N
Explanation:
1)
The work done by a force pushing an object is given by
[tex]W=Fd cos \alpha[/tex]
where
F is the magnitude of the force
d is the displacement of the object
[tex]\alpha[/tex] is the angle between the direction of the force and of the displacement
First of all, we need to find the magnitude of the force F. Since the block is moving vertically at constant velocity (= zero acceleration), the equation of motion of the block along the vertical direction is:
[tex]F sin \theta - \mu N - mg = 0[/tex] (1)
Where
[tex]\theta=27.0^{\circ}[/tex]
[tex]\mu N[/tex] is the force of friction, where
[tex]\mu=0.40[/tex] is the coefficient of friction
N is the normal reaction of the wall
(mg) is the weight of the block, where
m =2.0 kg is the mass of the block
[tex]g=9.81 m/s^2[/tex] is the acceleration of gravity
Along the horizontal direction, the equation of motion is:
[tex]F cos \theta = N[/tex] (2)
Substituting (2) into (1),
[tex]F sin \theta - \mu F cos \theta - mg =0[/tex]
And solving for F,
[tex]F(sin \theta - \mu cos \theta) = mg\\F=\frac{mg}{sin \theta - \mu cos \theta}=\frac{(2.0)(9.81)}{sin 27^{\circ} - 0.40 cos 27^{\circ}}=18.3 N[/tex]
Now we can calculate the work done by the force. Here we have
d = 1.0 m is the displacement
[tex]\alpha = 90^{\circ} - 27^{\circ} = 63^{\circ}[/tex] is the angle between the direction of the force and the displacement
Substituting,
[tex]W=(18.3)(1.0)(cos 63^{\circ})=8.3 J[/tex]
2)
The work done by gravity is equal to:
[tex]W_g = mg d cos \alpha[/tex]
where
m = 2.0 kg is the mass of the block
[tex]g=9.81 m/s^2[/tex]
d = 1.0 m is the displacement
[tex]\alpha=180^{\circ}[/tex], since the direction of gravity is downward while the displacement of the block is upward
Substituting,
[tex]W=(2.0)(9.81)(1.0)(cos 180^{\circ})=-19.6 J[/tex]
3)
Equation (2) found in part 1) tells that
[tex]N=F cos \theta[/tex]
which means that the normal force between the wall and the block is equal to the horizontal component of the pushing force on the block.
Here we have:
F = 18.3 N is the magnitude of the pushing force
[tex]\theta=27.0^{\circ}[/tex] is the angle of the force with the horizontal
Substituting, we find the normal force:
[tex]N=(18.3)(cos 27^{\circ})=16.3 N[/tex]
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The work done by the force on the block is 22.3 J. The work done by gravity is 19.6 J and the normal force between the block and the wall is 18.1 N.
Explanation:Firstly, we need to calculate the force that is applied (Force Applied) by taking the cosine of the angle (27.0◦) which is the force applied horizontally. Using the formula F_applied = m*g/cos(θ), where m=2.0 kg and g=9.81 m/s^2, we find that Force Applied = 22.3 N.
Next, the work done by the force on the block (Work Done) can be calculated by multiplying the Force Applied by the distance it moved (Force Applied x distance). Here, Work Done = 22.3 N x 1.0 m = 22.3 J.
The work done by gravity is obtained by multiplying the weight of the block by the distance it moves vertically (Work Done by Gravity). Here, Work done by Gravity = m*g*d = 2.0 kg * 9.81 m/s^2 * 1.0m = 19.6 J.
Finally, we calculate the magnitude of the normal force by multiplying the weight of the block by the cosine of the angle (m*g*cos(θ)) which equals to Normal Force = 2.0 kg * 9.81 m/s^2 * cos(27.0◦) = 18.1 N.
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An airplane changes its velocity uniformly from 150 m/s to 60 m/s in 15 s. Calculate:
a. Its acceleration
b. The distance traveled in that time
Answer:2.5
Explanation:
To a cyclist riding due west with a speed of 4 m/s a wind appears to
blow from south west. The wind appears to blow from south to a man running at 2 m/s in the same direction. What is the actual velocity of the wind ?
The actual velocity of the wind is 2 m/s due west.
Explanation:To find the actual velocity of the wind, we need to consider the velocities of both the cyclist and the man running.
Let's assume the cyclist's velocity is Vc = 4 m/s due west.
The man's velocity is Vm = 2 m/s due west.
Since the wind appears to blow from the south to the man running, the wind's velocity is equal to the difference between the velocities of the cyclist and the man running.
Therefore, the actual velocity of the wind is Vw = Vc - Vm = 4 m/s - 2 m/s = 2 m/s due west.
a cheetah ran 100 meters in 6 seconds. what is its average speed?
Answer:
A=16.6 repeating
explanation:
take 100/6 and solve just make sure your equation is set up correctly!
and you should get an answer of 16.6 repeating or 166 m/hour or 16.6 meters/per/hour
If a cheetah ran 100 meters in 6 seconds, then the average speed of the cheetah would be 16.67 meters per second.
What is speed?The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object.
As given in the problem a cheetah ran 100 meters in 6 seconds , then we have to find the average speed of the cheetah,
The distance traveled by the cheetah = 100 meters
The time is taken by the Cheetah to cover the distance = 6 seconds
The average speed of the cheetah = 100 / 6
= 16.67 meters per second
Thus, If a cheetah ran 100 meters in 6 seconds, then the average speed of the cheetah would be 16.67 meters per second.
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3-) A farm truck moves due east with a constant velocity of 9.50 m/s on a limitless, horizontal stretch of
road. A boy riding on the back of the truck throws a can of soda upward (Fig. P4.54) and catches the
projectile at the same location on the truck bed, but 16.0 m farther down the road.
(a) in the frame of reference of the truck, at what angle does the boy throw the can? .
(b) What is the initial speed of the can relative to the truck?
given,
constant velocity = 9.50 m/s
acceleration = 0
distance = 16 m
the time of flight
s = so + ut + 1/2at²
16 = 9.50 × t
t = 1.68 s
a) to catch the can the truck he must throw it straight up, at 0° to the vertical.
b) now,
yf = Yi + UyT + 1/2at²
0 = 0 + Uy * 1.68 - 1/2 * 9.8 * 1.68²
Uy = 8.23 m/s
3. The angular dispersion of a prism depends on
A. the index of refraction only B. the angle of
incidence as well as the index of refraction C. the
angle of incidence only D. the hi thickness of the
prism E, the prism angie.
Answer:
The angular dispersion of a prism depends on the index of refraction only.
Explanation:
The angular dispersion of a prism mainly depends upon the refractive index of a material. And this refractive index is dependent on the wavelength of light. Each colour possesses its own characteristic and the wavelength is also different. There has been a relation between refractive index of a material and wavelength of light higher the wavelength of the colour, greater would be the dispersion of light. As like when we passes light from a prism, according to this principle, the colours are dispersed.
All the other options are incorrect as cannot decide angle of dispersion.
Suggest possible explanations why reaction times are different for different people?
Everyone has a different reaction time because not everyone reacts the same to situations. Some people may be faster or slower than others. It could be a result of age, health, and how they take care of themselves physically.
Gender, age, physical fitness, level of exhaustion, distraction, alcohol usage, personality type, the limb utilized for the test, biological rhythm, health, and whether the stimulus is auditory or visual have all been found to have an impact on reaction time. Social and cultural factors on reaction time are irrelevant.
What is reaction time?A reaction is a deliberate, free response to an outside stimulus. The reaction time is the amount of time between the administration of an external stimulus and the appropriate motor response.
The period between the introduction of the stimulus and the emergence of the subject's proper voluntary response is referred to as the reaction time.
Typically, it is measured in milliseconds. It depicts the rate at which stimuli operate on a person's sensory system to produce neurophysiological, cognitive, and informational processes.
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If you could only see the lights in the circuit and the wires were covered from view, how could you determine the type of circuit the lights are arranged in?
To determine the type of circuit by only viewing the lights, one can observe the behavior when a light is manipulated; all lights going out suggests a series circuit, while others staying lit indicates a parallel circuit. Brightness changes with the addition or removal of lights also help identify the circuit type.
If you could only see the lights in a circuit and the wires were concealed, determining if the lights are arranged in a series or parallel circuit could be inferred by observing the behavior of the lights when one is manipulated. For example, if one light goes out and the others remain lit, it suggests a parallel circuit, as each light has its own path to the power source. However, if one light goes out and the rest do as well, this indicates a series circuit, where all lights are in a single path and the current must flow through each light consecutively.
Another method to determine the circuit type is by observing brightness changes when more lights are added or removed. In a series circuit, adding more lights would generally cause all lights to dim since the same current flows through each component and the total resistance increases. In contrast, in a parallel circuit, adding or removing lights would not change the brightness of the other lights, as each has an independent connection to the power source and their voltages remain constant.