initial height of the boy when he jump or dive is 5 meter
[tex]h_1 = 5 m[/tex]
now his final position is 2 yards above the surface
[tex]h_2 = 2 yards[/tex]
as we know that
[tex]1 yard = 0.9144 m[/tex]
[tex]2 yards = 1.83 m[/tex]
now by energy conservation we can say
change in potential energy = gain in kinetic energy
[tex]mg(h_1 - h_2) = \frac{1}{2} mv^2[/tex]
divide both sides by mass "m"
[tex]g*(5 - 1.83) = \frac{1}{2}*v^2[/tex]
[tex]v^2 = 2*9.8*(5 - 1.83)[/tex]
Now kinetic energy will be given as
[tex]KE = \frac{1}{2} mv^2[/tex]
[tex]KE = \frac{1}{2}*70 * 2*9.8*( 5 - 1.83)[/tex]
[tex]KE = 2175 J[/tex]
so his kinetic energy will be 2175 J
Identify two size dependent properties and two size independent properties of an iron nail
dependent volume and mass and independent melting point and bowing point
The two size dependent properties of iron are Volume and Mass and size independent properties are Melting point and Boiling point respectively.
The given problem is based on the properties of iron nail. The iron nails are made of steel and small amount of carbon for increasing the hardness.
The two size dependent properties of iron nails are as follows:
Volume: The volume of iron depends on the density of raw materials that are utilized for the production of raw iron.Mass : The mass is another dependent property, which varies along with the density as well as the volume of compositions.The size independent properties of the iron nails are as follows:
Melting point : Melting point is the property which depends on the surrounding temperature to overcome the inter-ionic interactions of material.Boiling point: The Boiling point of iron is around 2800 Degrees Celsius, which is also an independent property, irrespective of elementary compositions.Thus, we can conclude that the two size dependent properties of iron are Volume and Mass and size independent properties are Melting point and Boiling point respectively.
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Materials with resistivities between those of good conductors and those of insulators are called:
semiconductors ... silicon, germanium etc ...
Answer:
Semiconductors
Explanation:
The resistivity of conductors is low and the resistivity of insulators is high. The materials having resistivity between conductors and insulators are called semiconductors.
For example, silicon, gemanium, etc.
The elements having valency +4 are the semiconductors.
By increasing the temperature os a semiconductor, the conductivity increases or by the process of dopping the conductivity of semiconductor also increases.
A refrigerator removes 55.0 kcal of heat from the freezer and releases 73.5 kcal through the condenser on the back.How much work was done by the compressor
Here refrigerator removes 55 kcal heat from freezer
Refrigerator releases 73.5 kcal heat to surrounding
So here we can use energy conservation principle by II Law of thermodynamics
the law says that
[tex]Q_1 = Q_2 + W[/tex]
here we know that
[tex]Q_1[/tex] = heat released to the surrounding
[tex]Q_2[/tex] = heat absorbed from freezer
W = work done by the compressor
now using above equation we can write
[tex]73.5 = 55 + W[/tex]
[tex]W = 73.5 - 55[/tex]
[tex]W = 18.5 kcal[/tex]
So here compressor has to do 18.5 k cal work on it
Final answer:
The work done by the refrigerator's compressor, when it removes 55.0 kcal of heat from the freezer and releases 73.5 kcal through the condenser, is calculated to be 77,464 joules, after converting kcal to joules.
Explanation:
To determine the work done by the compressor in a refrigerator when it removes 55.0 kcal of heat from the freezer and releases 73.5 kcal through the condenser on the back, we can use the principle of conservation of energy. According to the first law of thermodynamics, the energy extracted from the freezer plus the work done by the compressor equals the energy released into the environment through the condenser.
The work done by the compressor (W) can be calculated by subtracting the heat removed from the cold reservoir (Qc) from the heat added to the hot reservoir (Qh).
First, we need to convert the heat quantities from kcal to joules because the standard unit of energy in physics is the joule (J). 1 kcal = 4184 J, therefore:
Qc = 55.0 kcal * 4184 J/kcal = 230120 J
Qh = 73.5 kcal * 4184 J/kcal = 307584 J
Now, calculate the work done:
W = Qh - Qc = 307584 J - 230120 J = 77464 J
Therefore, the compressor performed 77464 J of work in this process.
when the mass of an object increases, it gravitational pull(increases)(decreases)(stay the same
I'm pretty sure the answer is the gravitational pull increases
Answer:
if we increase the mass gravitational pull increases
Explanation:
According to gravitational law
Force between masses is given by [tex]F=\frac{Gm_1m_2}{R^2}[/tex], here G is gravitational constant [tex]m_1\ and\ m_2[/tex] are masses and R is distance between them
From the relation we cans see that gravitational pull is directly proportional to mass of the object
So if we increase the mass gravitational pull increases
use the drop down means to classify the elements as alkali metals alkaline eather metals or transition metals
Answer:
Nickel - Transitional Metal
Potassium- Alkali Metal
Cadmium- Transitional Metal
Calcium- Alkaline Earth Metal
Barium- Alkaline Earth Metal
Explanation:
Answer:
Nickel - Transitional Metal
Potassium- Alkali Metal
Cadmium- Transitional Metal
Calcium- Alkaline Earth Metal
Barium- Alkaline Earth Metal
Explanation:
which force causes acceleration(gravity)(friction)(velocity )(energy)
Gravity is the force that causes acceleration. Friction is a force that opposes motion, energy is a capacity to do work, and velocity is a measure of speed in a specific direction.
Explanation:Of the forces listed in your question, it is the force of gravity that causes acceleration. For example, when an object is dropped, it accelerates toward Earth under this force. This is popularly known as the force of gravity and represented as 'g'. The rate of acceleration due to gravity on Earth is approximately 9.81 m/s². Friction, on the other hand, actually opposes motion and may cause deceleration, if it is the only force acting on an object. Energy is a capacity to do work and does not directly cause acceleration, while velocity is a measure of speed in a specific direction and is a result, not a cause, of acceleration.
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what is the velocity of a car that traveled a total of 75 kilometers north in 1.5 hours?
50 kilometers should be it
Answer:
13.89 m/s
Explanation:
Velocity=Displacement/Time
Explanation:
75 km = 75000 m
1.5 hours = 5400 sec
Applying the formula
Velocity =75000 m 5400 s = 13.89 m/s
Please help me with question 1 of this reflections and refraction of waves worksheet, I’m really confused as to this labelling!
Here ya go. Check it out.
How many significant figures does the value 0.080 have? A. 1 B. 2 C. 3 D. 4
Answer:
2
Explanation:
The first person to answer was right
Help Please!
Could someone help me out with this one?
mass of the chair = 25 kg
Force required to start the motion = 165 N
Force required to maintain the motion = 127 N
part a)
when we applied the force to just start the motion then it is just equal to the limiting friction force
[tex]F_s = F[/tex]
now as we know that
[tex]\mu_s mg = 165[/tex]
[tex]\mu_s * 25 * 9.8 = 165[/tex]
[tex]\mu_s = \frac{165}{25*9.8}[/tex]
[tex]\mu_s = 0.67[/tex]
PART b)
when object has started motion then to maintain its motion we need external force to balance kinetic friction
[tex]F_k = F[/tex]
now as we know that
[tex]\mu_k mg = 127[/tex]
[tex]\mu_k * 25 * 9.8 = 127[/tex]
[tex]\mu_k = \frac{127}{25*9.8}[/tex]
[tex]\mu_k = 0.52[/tex]
a car with a mass of 1400 kg is traveling at a speed of 40 m/s. what is it's momentum
I believe the answer is 56000 kgm/s
Which cloud type is confined to the middle height range?
It would be alto. I hope that is one of your answers.
Which cloud type is confined to the middle height range?
A. cumulonimbus
B. cirrus
C. cirrostratus
D. altostratus
Answer:
D. Altostratus
Explanation:
Altostratus cloud is a type of physical stratiform: a cloud which can be identified by its gray or blueish gray colour. It is a middle level cloud, that is associated with a storm and excessive rain or snow. It contains ice crystals and water droplets, and it is lighter in colour when compared to nimbostratus, while it is darker in appearance when compared to cirrostratus.
A moving freight car collides with an identical one that is at rest. If momentum is conserved, what happens to the second car after the collision?
There will be two different possiblites as
May be one is in rest or other move
May be both will be in motion
ExpalanationAccording to Conservation Law of Momentum, when the two objects collide with each other, they transferred their kinetic energy to keep their momentum before or after collisions remain constant. In the present example, one moving car collides with another car which is at rest and has the same weight. There will be two possibilities after the collision as an elastic collision or perfect inelastic collision. In the elastic collision, the one car will adopt the rest position after the collision and transfer it K.E to make the rest car at the movable position. In the perfect inelastic collision, both cars will move after the collision.
Answer:
It attains the same speed as the first car.
A stuntwoman is going to attempt a jump across a canyon that is 77 m wide. The ramp on the far side of the canyon is 25 m lower than the ramp from which she will leave. The takeoff ramp is built with a 15º angle from horizontal. If the stuntwoman leaves the ramp with a velocity of 28 m/s, will she make the jump? Why?
initial speed of the stuntman is given as
[tex]v = 28 m/s[/tex]
angle of inclination is given as
[tex]\theta = 15 degree[/tex]
now the components of the velocity is given as
[tex]v_x = 28 cos15 = 27.04 m/s[/tex]
[tex]v_y = 28 sin15 = 7.25 m/s[/tex]
here it is given that the ramp on the far side of the canyon is 25 m lower than the ramp from which she will leave.
So the displacement in vertical direction is given as
[tex]\delta y = -25 m[/tex]
[tex]\delta y = v_y * t + \frac{1}{2} at^2[/tex]
[tex]-25 = 7.25 * t - \frac{1}{2}*9.8* t^2[/tex]
by solving above equation we have
[tex]t = 3.12 s[/tex]
Now in the above interval of time the horizontal distance moved by it is given by
[tex]d_x = v_x * t[/tex]
[tex]d_x = 27.04 * 3.12 = 84.4 m[/tex]
since the canyon width is 77 m which is less than the horizontal distance covered by the stuntman so here we can say that stuntman will cross the canyon.
The resistance of an electric device is 40,000 microhms convert that measurement to ohms
The answer would be 0.04ohms.
Answer:
The resistance of an electric device is 0.04 ohms.
Explanation:
Given that,
Resistance = 40,000 micro ohms
We need to convert micro ohms to ohms
We know that,
[tex] 1 micro ohms = 10^{-6}\ ohms[/tex]
Therefore,
[tex]40000\ micro ohms=40000\times10^{-6}\ ohms[/tex]
[tex]40000\ micro ohms=0.04\ ohm[/tex]
Hence, The resistance of an electric device is 0.04 ohms.
A 1.00x10^3 crate is being pushed across a level floor at a constant speed by a force
Answer:
The answer is 0.39 m/s ²
Explanation:
Since the box moves with steady speed,
Friction=force in even direction=260*Cos20=244.3N
Ordinary force=mg+FSinθ=1089N
μN=f
μ=244.3/1089=0.224
N=mg-FSinθ=911.1N
a=(260 Cos20-0.224*911.1)/(1000/9.8)=0.39m/s²
(this is somehow part of my science unit, dont ask why)
The height of a coffee mug would be about:
50 mm
20 cm
8 m
0.1 km
Answer:
Height of coffee mug = 5 cm
Explanation:
Changing all the data given in to unit cm
50 mm = 5 cm
20 cm = 20 cm
8 m = 800 cm
0.1 km = 100 m = 10000 cm
Since we need to find the height of coffee mug, it's height will not be more than 10 cm.
So 5 cm is the correct choice.
what is the sum of all forces acting on an object and direction
The sum of all forces on an object is the net force or resultant force. If all the forces cancel out , resultant force is zero , otherwise unbalanced force will cause acceleration of object .
Force is the vector, has both direction and magnitude.
The sum of all forces acting on an object is called the net force. It takes into account the magnitude and direction of each individual force. Internal forces cancel out, resulting in a net force of zero, while external forces are added together vectorially to find the net force.
Explanation:The sum of all forces acting on an object and their direction:
In physics, the sum of all forces acting on an object is called the net force. The net force takes into account the magnitude and direction of each individual force. To find the net force, you need to consider both internal and external forces.
Internal Forces:
Internal forces are the forces between different parts of the object. According to Newton's third law, these forces always come in pairs with equal magnitudes but opposite directions. When you add all the internal forces together, they cancel out and the sum of all internal forces is zero.
External Forces:
External forces are the forces applied to the object by external sources. The sum of all external forces is equal to the net force acting on the object. To calculate the net force, you need to add up all the external forces vectorially, taking into account their magnitudes and directions.
Val is comparing the gravitational force and the electromagnetic force
Which describes the electromagnetic force ONLY? Check all that apply
The correct answers are:
- is repulsive
- produces light
- produces electricity
Explanation:
The electromagnetic force can be either attractive (when the two charges have opposite sign) or repulsive (when the two charges have same sign). On the contrary, the gravitational attraction is always attractive, so "is repulsive" is a property of the electromagnetic force only.
Moreover, as a result of electromagnetic interactions, photons can be produced (so, light, since light consists of photons), as well as electrons or other charged particles (so, electricity, since electrical currents consists of electrons or charged particles), while the gravitational force is not able to produce light or electrical currents.
If Val is comparing the gravitational force and the electromagnetic force, what applies is:
- is repulsive- produces light- produces electricityHow to get the answerElectric and Magnetic Interaction: The electromagnetic force encompasses both electric and magnetic interactions. It is responsible for electric attraction and repulsion between charged particles and the behavior of magnets.
2. Acts on Charged Particles: The electromagnetic force acts on charged particles, which can be positively charged (protons), negatively charged (electrons), or both. Like charges repel each other, while opposite charges attract.
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The _______ force is responsible for the way that electrical charges and magnets interact with each other
Answer:
Electromagnetic energy/force
Explanation:
Electromagnetism: Electromagnetism is an interaction that occurs between particles with electric charge via electromagnetic fields. It combines electrostatics and magnetism, distinct but closely intertwined phenomena. The electromagnetic force is dominant in the interactions of atoms and molecules.
Electric Forces: Electric forces cause attraction between particles with opposite charges and repulsion between particles with the same charge. These forces are described by Coulomb’s law for electricity.
Magnetic Forces: Magnetism arises from the interaction between charged particles in relative motion. The magnetic force acts perpendicular to both the velocity of the charged particle and the magnetic field.
Applications: Electromagnetism plays a vital role in technology, including electrical energy production, communication (fibre optics and wireless), sensors, computation, and mechanical motors. It also explains chemical bonding and the behaviour of atoms and molecules.
In summary, electromagnetic force governs the behaviour of charged particles and underpins much of our understanding of the physical world
Vector A⃗ points in the positive y direction and has a magnitude of 12 m. Vector B⃗ has a magnitude of 33 m and points in the negative x direction.
Find the direction of A⃗ + B⃗ .
Find the magnitude of A⃗ + B⃗
vector A has magnitude 12 m and direction +y
so we can say
[tex]\vec A = 12 \hat j[/tex]
vector B has magnitude 33 m and direction - x
[tex]\vec B = -33 \hat i[/tex]
Now the resultant of vector A and B is given as
[tex]\vec A + \vec B = 12 \hat j - 33 \hat i[/tex]
now for direction of the two vectors resultant will be given as
[tex]\theta = tan^{-1}\frac{12}{-33}[/tex]
[tex]\theta = 160 degree[/tex]
so it is inclined at 160 degree counterclockwise from + x axis
magnitude of A and B will be
[tex]R = \sqrt{A^2 + B^2}[/tex]
[tex]R = \sqrt{12^2 + 33^2} = 35.11 m[/tex]
so magnitude will be 35.11 m
Final answer:
The direction of the resultant vector A› + B› is 20.1° north of the negative x-axis, and its magnitude is approximately 35.1 m.
Explanation:
To find the direction and magnitude of the resultant vector A› + B›, we can use vector addition. Vector A› points in the positive y direction and has a magnitude of 12 m, so its components are (0, 12). Vector B› has a magnitude of 33 m and points in the negative x direction, with components (-33, 0). By adding these components, we get the resultant vector R = A + B = (0 - 33, 12 + 0) = (-33, 12).
To find the magnitude of the resultant vector, we use the Pythagorean theorem:
|R| = √((-33)^2 + (12)^2) = √(1089 + 144) = √(1233) ≈ 35.1 m
The direction of resultant vector R can be found by calculating its angle θ with respect to the negative x-axis (since the x component is negative) using the tangent function:
θ = arctan(|12| / |-33|) = arctan(12 / 33) ≈ 20.1°
The direction is therefore 20.1° above (north of) the negative x-axis.
What is the definition of fluid friction?
the force that resists the movement of a solid object through a fluid (liquid or gas). Hope this helps.
Fluid friction, or drag, is the force resisting the motion of an object through a fluid like water or air. It depends on factors such as fluid viscosity, object shape and speed, and contact surface area. Examples include a boat moving through water and air resistance on a falling parachutist.
Fluid friction, also known as drag, is the force that opposes the motion of an object through a fluid (liquid or gas). This type of friction occurs when layers of the fluid move at different speeds or directions. For instance, a boat moving through water experiences fluid friction between the hull and the water, which resists its motion.
Fluid friction is influenced by several factors, including the viscosity of the fluid, the shape and speed of the object, and the surface area in contact with the fluid. An example of this is air resistance, which acts on a parachutist falling through the atmosphere, slowing their descent due to the opposition force of the air.
Suppose you dissolve 12.8 g of one substance in 11 g of another. Is this reasonable? Explain
Answer:
No, its not reasonable.
Explanation:
The substance that is to be dissolved is known as solute. The substance that is dissolving is known as solvent.
The amount of solvent in the mixture should be greater than that of solute.
Suppose we are taking a solvent in a beaker and we are continuously adding solute in it. Initially the solute dissolve quickly. At some point the solute stops dissolving in the solvent. This is known as saturation point of the solvent. After saturation point if solute is added further it does not dissolve in the solvent.
So, its not possible to dissolve 12.8 g of one substance in 11 g of another.
Soundproof rooms take advantage of which property of waves
The answer is Absorption.
The Absorption one
and im writing more cause 20 character thing
Frim the castle wall 20 m high shot an arrow. The initial speed of the bow is 45 m/s directed 40 degrees above horizontal. Find the range and hI e final velocity
Answer:
Range of arrow = 225.09 meter
Final horizontal velocity = 34.47 m/s
Explanation:
We have equation of motion [tex]s=ut+\frac{1}{2} at^2[/tex], where u is the initial velocity, t is the time taken, a is the acceleration and s is the displacement.
Considering the vertical motion of arrow ( up direction as positive)
We have u = 45 sin40 = 28.93 m/s, s = -20 m, a = acceleration due to gravity = [tex]-9.8m/s^2[/tex].
[tex]-20=28.93*t-\frac{1}{2} *9.8*t^2\\ \\ 4.9t^2-28.93t-20=0[/tex]
t = 6.53 seconds or t = -0.63 seconds
So time = 6.53 seconds.
Considering the horizontal motion of arrow
u = 45 cos 40 = 34.47 m/s, t = 6.53 s, a = [tex]0m/s^2[/tex]
[tex]s=34.47*6.53+\frac{1}{2} *0*6.53^2\\ \\ s=225.09m[/tex]
So range of arrow = 225.09 meter
Horizontal velocity will not change , final horizontal velocity = 34.47 m/s.
A force of 150N is inclined at 50° t The horizontal direction. Find it's components in horizontal and vertical direction
The solution is attached below.
You are standing at a subway platform when a subway passes, sounding its whistle. If you observe the whistle to be at 12750Hz when it is approaching you and at 10750Hz after it passes,
As per doppler's Effect of sound we can say when subway is approaching the platform we will have
[tex]f_1 = f_o* \frac{v}{v- v_s}[/tex]
[tex]12750 = f_o* \frac{340}{340 - v_s}[/tex]
Similarly we can find the frequency when subway is passing away with same speed from us
[tex]f_2 = f_o* \frac{v}{v + v_s}[/tex]
[tex]10750 * f_o* \frac{340}{340 + v_s}[/tex]
now we can find the ratio of two
[tex]\frac{12750}{10750} = \frac{340 + v_s}{340 - v_s}[/tex]
[tex]1.186*(340 - v_s) = 340 + v_s[/tex]
[tex]403.26 - 1.186 v_s = 340 + v_s[/tex]
[tex]63.26 = 2.186 v_s[/tex]
[tex]v_s = \frac{63.26}{2.186}[/tex]
[tex]v_s = 28.94 m/s[/tex]
So the speed of subway is 28.94 m/s
a sprinter with a mass of 70 kg accelerates at a rate of 5 m/
[tex] {s}^{2} [/tex]
. What force is the sprinter exerting
F = ma
= 70kg × 5ms⁻²
F =350N
The sprinter is exerting a force of 350 Newtons.
Explanation:The force exerted by the sprinter can be calculated using Newton's second law, which states that force is equal to mass multiplied by acceleration. In this case, the sprinter's mass is 70 kg and the acceleration is 5 m/s². So, the force exerted by the sprinter is:
Force = mass x acceleration
Force = 70 kg x 5 m/s²
Force = 350 N
Therefore, the sprinter is exerting a force of 350 Newtons.
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A ferry approaches shore, moving north with a speed of 6.2 m/s relative to the dock. A person on the ferry walks from one side of the ferry to the other, moving east with a speed of 1.5 m/s relative to the ferry. What is the speed of the person relative to the dock?
Speed of Ferry is towards North with magnitude 6.2 m/s
Here if we assume that North direction is along Y axis and East is along X axis then we can say
[tex]\vec v_f = 6.2 \hat j[/tex]
Now a person walk on ferry with speed 1.5 m/s towards east with respect to Ferry
so it is given as
[tex]\vec v_{pf} = 1.5 \hat i[/tex]
also by the concept of relative motion we know that
[tex]\vec v_{pf} = \vec v_p - \vec v_f[/tex]
now plug in all values in it
[tex]1.5 \hat i = \vec v_p - 6.2 \hat j[/tex]
[tex]\vec v_p = 1.5 \hat i + 6.2 \hat j[/tex]
now if we need to find the speed of the person then we need to find its magnitude
so it is given as
[tex]v = \sqrt{1.5^2 + 6.2^2}[/tex]
[tex]v = 6.37 m/s[/tex]
A time-varying magnetic field is caused by which of the following?
-current carrying wires carrying a constant current
-a positive test charge moving through a constant electric field
-fluctuating electric fields
-the interaction with earth’s magnetic field
A time-varying magnetic field can be caused by fluctuating electric fields.
Answer:
-fluctuating electric fields
Explanation:
As we know that electric field and magnetic field is related by the equation given as
[tex]\int E. dl = -\frac{d\phi}{dt}[/tex]
here we know that
[tex]\phi = B.A[/tex]
now we have magnetic field is time varying
[tex]\int E.dl = -A\frac{dB}{dt}[/tex]
now for closed loop of radius "r" we will have
[tex]E(2\pi r) = - A\frac{dB}{dt}[/tex]
[tex]E = -\frac{A}{2\pi r}\frac{dB}{dt}[/tex]
so here this produce electric field as per above formula and it is also known as non conservative electric field.