Answer:
4200 kJ
10 kg/min
Explanation:
70 kW means 70 kJ per second. So in a minute, the amount of heat generated at the brake is:
70 kJ/s × 60 s/min = 4200 kJ
Heat = mass × specific heat capacity × increase in temperature
4200 kJ = m × 4.184 kJ/kg/C × 100 C
m = 10 kg
So every minute, 10 kg of water is heated. So the mass flow is 10 kg/min.
A hollow glass sphere has a density of 1.30g/cm cubic at 20°C.Glycerine has a density of 1.26g/cm cubic at 20°C.At what temperature would the sphere begin to float in glycerine?
Given coefficient of volume expansion of glycerine is 53 × 10^-5/ °C.
The glass sphere will begin to float in glycerine when the glycerine's density decreases below that of the sphere's density of 1.30 g/cm³ upon heating. Using the coefficient of volume expansion, we can calculate the temperature at which this occurs.
Explanation:To determine at what temperature the hollow glass sphere would begin to float in glycerine, we need to consider the density changes of glycerine with temperature. Since the sphere's density is 1.30 g/cm³ and the density of glycerine is 1.26 g/cm³ at 20°C, we look for the temperature at which the glycerine's density drops below that of the sphere. Using the formula ΔV = βV₀ΔT (where ΔV is the change in volume, V₀ is the initial volume, β is the coefficient of volume expansion of glycerine, and ΔT is the change in temperature), we can calculate the new density of glycerine at different temperatures and find the point where it is equal to the sphere's density.
Since density is mass over volume, as volume increases due to temperature rise, density decreases. As glycerine warms up and expands, its density will decrease: Density_glycerine(T) = Density_glycerine(20°C) / (1 + βΔT). We set this equal to the sphere's density to solve for the temperature increase. When glycerine's density is just less than that of the glass sphere, the sphere will begin to float.
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Write differences between tornado and typhoon
The difference lies in their size, wind velocity, rate of travel, and duration. A tornado reaches rotating speeds up to 300 miles per hour, travels between 25 and 40 miles per hour, and generally lasts for a few minutes (although it can exist for hours). A typhoon (the term used in the Pacific for a hurricane) has winds that vary from 75 to 200 miles per hour, moves between 10 and 20 miles per hour, has a diameter up to 600 miles, and exists from days up to a week. A tornado generally forms several thousand feet above Earth’s surface, usually during warm, humid weather. A typhoon breeds in low-altitude belts over the ocean, generally from 5 to 15 degrees latitude north or south.
A rod of length r and mass m is pivoted at its center, and given an angular velocity, ω1. What would be the angular velocity of a second rod, which has the same angular momentum as the first, but whose length is 3r and whose mass is 2m?
Answer:
ω₁ / 18
Explanation:
Angular momentum is the moment of inertia times the angular velocity.
L = Iω
For a rod pivoted at its center, the moment of inertia is:
I = mr² / 12
where m is the mass and r is the length.
For the first rod:
L = (mr² / 12) ω₁
For the second rod:
L = ((2m) (3r)² / 12) ω₂
L = (18mr² / 12) ω₂
They have the same angular momentum, so:
(mr² / 12) ω₁ = (18mr² / 12) ω₂
mr² ω₁ = 18mr² ω₂
ω₁ = 18 ω₂
ω₂ = ω₁ / 18
The angular velocity of a second rod is ω₁ / 18.
What is angular momentum?Angular momentum is the moment of inertia times the angular velocity.
L = Iω
For a rod pivoted at its center, the moment of inertia is I = mr² / 12
where m is the mass and r is the length.
A rod of length r and mass m is pivoted at its center, and given an angular velocity, ω1. the second rod has the same angular momentum as the first, but whose length is 3r and whose mass is 2m.
For the first rod, angular momentum is
L = (mr² / 12) ω₁
For the second rod, angular momentum is
L = ((2m) (3r)² / 12) ω₂
L = (18mr² / 12) ω₂
They have the same angular momentum,
(mr² / 12) ω₁ = (18mr² / 12) ω₂
mr² ω₁ = 18mr² ω₂
ω₁ = 18 ω₂
ω₂ = ω₁ / 18
Thus, the angular velocity of a second rod is ω₁ / 18.
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What is Scientific Notation?
A. It is a way to abbreviate very large or very small numbers.
O
B. It is a special way of writing that looks scientific.
O
C. It is writing scientific summaries in a journal.
D. It is a way of making numbers scientific.
Answer:
A. It is a way to abbreviate very large or very small numbers.
Explanation:
Scientific Notation is a way to abbreviate very large or very small numbers.
find the weight density 1.00 qt. of liquid weighing 4.00 lb.
Answer:
p = 1.91722 g/cm3
Explanation:
Density is p=m/V, where density (p) is equal to mass (m) divided by volume (V).
Answer/Explanation:
I've worked out that p = 1.91722 g/cm3
Density is p=m/V, where density (p) is equal to mass (m) divided by volume (V).
If the mass of an object increases, predict what will happen to the coefficient of sliding friction.
Answer:
The coefficient of friction remains the same. The mass affects the force of friction, however the coefficient of friction depends the structural properties of the surfaces of the object and the floor. Therefore, the mass has no effect of the coefficient of friction.
The coefficient of sliding friction is generally unaffected by the mass of the object.
The coefficient of sliding friction, denoted by μ, is a dimensionless scalar value that represents the ratio of the force of friction between two bodies and the normal force pressing them together. It is determined by the properties of the surfaces in contact, such as their roughness and the materials they are made of, and is independent of the area of contact or the mass of the objects involved.
The formula for the force of friction [tex](F_friction)[/tex] is given by:
[tex]\[ F_{\text{friction}} = \mu \times N \][/tex]
where[tex]\( N \)[/tex] is the normal force, which is equal to the gravitational force on the object if it is resting on a horizontal surface. The gravitational force [tex](F_gravity)[/tex] is the product of the mass of the object (m) and the acceleration due to gravity (g):
[tex]\[ F_{\text{gravity}} = m \times g \][/tex]
Since the normal force is equal to the gravitational force, an increase in mass would increase the normal force, and consequently, the force of friction would also increase, as they are directly proportional. However, the coefficient of friction itself remains constant as it is a property of the surfaces in contact.
In summary, while the mass of an object affects the magnitude of the frictional force because it changes the normal force, it does not affect the coefficient of sliding friction. The coefficient of sliding friction remains constant for a given pair of surfaces in contact.
What is the volume of 282 g of metal with a density of 11.7 g/cm32
Answer:
24.1025641
Explanation:
Density = Mass ÷ Volume
We need to work out volume so the equation is going to be ⇒
Mass ÷ Density
Mass = 282 g
Density = 11.7
282 ÷ 11.7 = 24.1025641
9. At the amusement park, a blue bumper car crashes into a red bumper car. Which of the
following statements about their momentum is accurate?
A. There is less overall momentum after the collision.
B. The momentum of the red car is destroyed as it is hit.
C. There is greater overall momentum after the collision.
D. The overall momentum stavs the same before and after the collision
Answer:A)
Explanation:
Well It makes the Most sense. The momentum of the Cars were lessened due to the hit.
B is wrong because not only did the red car crash but so did the blue so the real answer should be both.
C makes no sense at all.
D The momentum is lost after collision so it is not the same, so this is false also.
HOPE THIS HELPS! :)
2 Points
An athlete jumps with a speed of 4 m/s at an angle of 23º. How long does the
athlete stay in the air?
O
A. 0.32 s
B. 0.92 s
C. 0.55 s
D. 0.75 s
SUBMIT
Calculate the vertical component of the athlete's speed:
Vy = Vsin(θ)
Vy is the vertical component of the speed, V is the speed, and θ is the angle the athlete jumps off the ground at.
Given values:
V = 4m/s
θ = 23°
Plug in these values and solve for Vy:
Vy = 4sin(23°) = 1.563m/s
Let us use this kinematics equation for the athlete's vertical motion:
H = Vt + 0.5At²
H is the height, t is time, V is the initial vertical velocity, and A is acceleration.
Given values:
V = 1.563m/s
A = -9.81m/s² (acceleration due to gravity)
Plug in these values:
H = 1.563t - 4.905t²
We want to know the athlete's airtime, or when they reach the ground, ie calculate a time t when H = 0m. So let us substitute H = 0 and solve for t:
1.563t - 4.905t² = 0
t = 0.3187, 0
Reject t = 0s
t = 0.3187s
Choice A
Which of the following could be vector magnitudes?
Answer:
Both A and D
Explanation:
Vector magnintude contains both speed and direction and so do these answer choices of 15km and 30m/s
Answer:
A and D
Explanation:
A vector magnitude has a magnitude and a direction Then 15 km are a magnitude that could have a direction for example 15 km in north direction.
The same happends with 30 m/s its a magnitude that could have a direction.
In the case of the option B 25 mililiters is a scalar magnitude because is a volumen then we can not define a direction, and the same for the option C 15 hours.
which of the following is the best definition of ethics?
A) guidelines for good behavior
B) laws that require scientists to research certain things
C) the needs of society
Answer:
B) laws that require scientists to research certain things
The best definition of ethics is A) guidelines for good behavior.
What are Ethics?Ethics are a set of principles that guide our behavior and help us to make decisions about what is right and wrong. Ethics are based on our beliefs about what is good and bad, and they help us to live our lives in a way that is morally acceptable.
Laws are also important for good behavior, but they are not the same as ethics. Laws are rules that are enforced by the government, while ethics are guidelines that we follow voluntarily. Ethics are often more general than laws, and they can be applied to a wider range of situations.
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A particle moves in horizontal circle of radius 15 cm inside an inverted smooth hollow
hemisphere as shown in FIGURE 6.6.
calculate speed of particle
The speed of the particle moving in a horizontal circle within a hemisphere can't be calculated without knowing the mass of the particle or the centripetal force. The force necessary for such motion is given by the equation F = mv^2/r, where F denotes force, m is mass, v is speed and r is radius.
Explanation:The question asks for the speed of the particle moving in a circular path inside a hollow hemisphere. This is a classical mechanics problem in
Physics
, specifically dealing with centripetal force. According to Physics, for an object moving in a circle of radius r at a speed v, the centripetal force necessary to keep the object moving in this path is mv^2/r, where m is the mass of the object. However, the exact speed can't be calculated without knowing either the mass of the particle or the centripetal force involved.
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A natural resource that is in limited supply is known as a _________________.
Answer:
Limited Resources
Answer:I’m sure it lime red resources
Explanation:
A construction worker is carrying a load of 40 kilograms over his head and is walking at a constant velocity. If he travels a distance of 50 meters, how
much work is being done?
Answer: 2000
Explanation:
Answer:
0 J
Explanation:
Work is force times distance in the direction of the force (the dot product of the force and distance vectors).
W = F · d
Another way to write it is force times distance times the cosine of the angle between the force and distance vectors:
W = Fd cos θ
The force the worker is applying is vertical (there's no horizontal force because he is moving at constant velocity). The direction he moves in is horizontal. The two vectors are perpendicular, so there is no force component in the direction of motion, so there is no work being done.
as a hurricane or tropical storm approaches your location, it's forward speed decreases from 20 kt to 10 kt. How might this affect rainfall?
Answer:
The correct answer is c. More total rainfall from a slower moving storm.
When the the forward speed of the hurricanes and tropical storms slows down they tend to increase the rainfall. Because of the slow movement the storm can be for few days over a given region and produce rainfall without stopping, thus create major flooding, pilling up of the coastal water, and produce persistent strong winds even though they have decreased in their forward speed.
Explanation:
Answer:
c. More total rainfall from a slower moving storm.Explanation:
Choices for this question are
a. Less flooding because rain will have more time to soak into the ground.
b. Less total rainfall from a weakening system.
c. More total rainfall from a slower moving storm.
d. Shorter period under the rainbands.
When hurricane's forward speed decreases, they will last more time, because their energy is gonna last more. This means that the rainfall will also last more days. Even-though, slower hurricanes tend to last more time because of this, so, the chances of happening floods is higher, because the rainfall will continue for more days.
3- (a) What is the period of rotation of Earth in seconds? (b) What is the angular velocity of Earth? (c) Given that Earth has a radius of 40,075 km at its equator, what is the linear velocity at Earth’s surface?
Explanation:
a) The Earth makes 1 rotation in 24 hours. In seconds:
24 hr × (3600 s / hr) = 86400 s
b) 1 rotation is 2π radians. So the angular velocity is:
2π rad / 86400 s = 7.27×10⁻⁵ rad/s
c) The earth's linear velocity is the angular velocity times the radius:
40075 km × 7.27×10⁻⁵ rad/s = 2.91 km/s
(a)The period of rotation of Earth in seconds will be 86400 second.
(b) The angular velocity of Earth will be 7.27 ×10⁻⁵ sec.
(c)The linear velocity at Earth’s surface will be 2.91 km/sec.
What is angular velocity?The rate of change of angular displacement is defined as angular velocity.
It is stated as follows:
ω = θ t
Where,
θ is the angle of rotation,
t is the time
ω is the angular velocity
The period of rotation of Earth in seconds is found as;
As we know, the complete rotation of the earth took 24 hours.
The total rotational time is converted into the second;
1 hour = 3600 sec
24 hour=24×3600
T= 86400 second
The angular velocity of Earth is;
[tex]\rm \omega= \frac{2\pi}{T} \\\\\ \omega = \frac{2\times 3.14}{86400}\\\\ \omega = 7.27 \times 10^{-5} \ rad/sec[/tex]
The linear velocity at Earth’s surface is found as;
v=r ×ω
v=40075 ×7.27 ×10 ⁻⁵
v=2.91 km/sec
Hence, period of rotation, angular velocity of earth and linear velocity at Earth’s surface 86400 second,7.27 ×10⁻⁵ sec and 2.91 km/sec respectively.
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a meteor is falling towards the earth. If the mass and radius of the earth are 6×10^24 kg and 6.4×10^6 m respectively. Find the hieght of the meteor where its acceleration due to gravity is 4m/s^2
Answer:
3.6×10⁶ m
Explanation:
Newton's law of universal gravitation states that the force between two masses is:
F = GMm / r²
where G is the universal constant of gravitation (6.67×10⁻¹¹ m³/kg/s²),
M is the mass of one object
m is the mass of the other object,
and r is the distance between the center of masses of the objects.
The force acting on the meteor is:
∑F = ma
GMm / r² = ma
GM / r² = a
Given M = 6×10²⁴ kg and a = 4 m/s²:
(6.67×10⁻¹¹ m³/kg/s²) (6×10²⁴ kg) / r² = 4 m/s²
r = 10⁷ m
The distance from the meteor to the center of the Earth is 10⁷ m. We want to know what the height of the meteor is (distance to the surface of the Earth). So we need to subtract the Earth's radius.
h = 10⁷ m − 6.4×10⁶ m
h = 3.6×10⁶ m
A ball is moving at a speed of 5 mi/h along a frictionless surface. It will continue moving at this speed as long as (Select all that apply)
A) something keeps pushing it because it requires a force to continue its motion
B) balanced forces act up on it because an unbalanced force will change its motion
C) something keeps pulling it because it requires a force to continue its motion
D) no forces act upon it because it’s inertia will allow it to continue moving at a constant velocity
The ball will continue moving at this same speed as long as no external forces act upon it because it’s inertia will allow it to continue moving at a constant velocity. So, option D is correct.
What is meant by inertia ?Inertia of an object is defined as the tendency of the object to continue its state of rest or uniform motion.
Here,
The ball is moving along a frictionless surface with a speed of 5 m/h.
This motion of the ball will be continued as long as no external force acts on it. This is because,
According to Newton's first law, a moving body will continue its state of uniform motion unless it is acted upon by an external force. So, an external force like a push or pull is required to change the speed of the ball as well as to change the direction of motion of the ball. Therefore the ball will continue its motion with the same speed and direction due to its property of inertia of motion.
Hence,
The ball will continue moving at this same speed as long as no external forces act upon it because it’s inertia will allow it to continue moving at a constant velocity.
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Final answer:
A ball on a frictionless surface will maintain its speed of 5 mi/h due to inertia and balanced forces, meaning no additional force is required to keep it in motion. Statements B and D accurately describe this scenario according to Newton's laws of motion.
Explanation:
A ball moving at a speed of 5 mi/h along a frictionless surface will continue moving at this speed if certain conditions are met. According to physics principles, particularly Newton's laws of motion, an object in motion will stay in motion at a constant speed in a straight line unless acted upon by a net force. Therefore, the correct answers are:
(B) Balanced forces act upon it because an unbalanced force will change its motion.(D) No forces act upon it because its inertia will allow it to continue moving at a constant velocity.Both statements B and D are true because in the absence of external forces, such as friction, the ball's inertia will keep it moving indefinitely at the same speed and in the same direction. No additional force is needed to maintain its motion; on the contrary, it requires a force to change its state of motion as stipulated by the law of inertia.
If the mass of an object is 6 kg and its momentum is 72 kgm/s, what is its velocity?
A. 18 m/s
B. 12 m/s
C. 9 m/s
D. 72 m/s
Answer:
B. 12 m/s
Explanation:
Momentum is mass times velocity
p = mv
Given p = 72 kgm/s and m = 6 kg:
72 kgm/s = (6 kg) v
v = 12 m/s
Final answer:
The correct answer is B. 12 m/s.
Explanation:
The question provided is asking about finding the velocity of an object when its mass and momentum are known. The formula for momentum (p) is the product of mass (m) and velocity (v), which is expressed as p = m × v. Given that the momentum (p) is 72 kg·m/s and the mass (m) is 6 kg, we can solve for velocity (v) by rearranging the formula: v = p / m.
Plugging in the values, we get v = 72 kg·m/s divided by 6 kg, which simplifies to 12 m/s. Therefore, the correct answer is B. 12 m/s.
Four identical light bulbs (B1, B2, B3, and B4) and
six voltmeters are connected as shown in the figure.
Assuming that V is as its original reading when all bulbs
are working and V' is as its reading when B2 is caught
on fire. If B2 were to be caught on fire, the reading of V
is ...
Answer:
(D) V > V' > 1/2 V
Explanation:
When B₂ is in the circuit, the equivalent resistance is:
Req = R + (1/R + 1/2R)^-1
Req = R + 2/3 R
Req = 5/3 R
So the current in B₁ is:
I = V/R
I = V₀ / (5/3 R)
I = 3/5 V₀/R
Therefore, the reading of V₁ is:
V = IR
V₁ = (3/5 V₀/R) R
V₁ = 3/5 V₀
V₁ = 0.6 V₀
After B₂ is removed, the equivalent resistance is:
Req = 3 R
So the current in B₁ is:
I = V/R
I = V₀ / (3 R)
I = 1/3 V₀/R
Therefore, the new reading V₁' is:
V = IR
V₁' = (1/3 V₀/R) R
V₁' = 1/3 V₀
V₁' = 0.333 V₀
The new voltage is less than the original voltage, but more than half the original voltage. The answer is D.
what are the 12 colors of the spectrum called?
Answer: The correct answer is : Hues
Explanation: The spectrum is made up of three primary light colors that are red, green and blue. For three secondary colors that are yellow, cyan and magenta. For six tertiary colors that are orange, lemon green, turquoise, light blue, violet and teal. The spectrum does not contain all the colors that human eyes and the brain can distinguish, for example magenta, pink and coffee are not in the visible spectrum because the mixing of several wavelengths, mainly dark reds, is required .
The visible spectrum includes the colors red, orange, yellow, green, blue, indigo, and violet, with specific wavelengths assigned to each. These colors are often observed in a rainbow. While indigo is sometimes included, the main colors are typically red, orange, yellow, green, blue, and violet.
The visible spectrum of light consists of colors that are produced by visible light of specific wavelengths. The primary colors that we see in a rainbow and that can be produced by narrow bands of wavelengths include:
Red (620 to 750 nm), Orange (590 to 620 nm), Yellow (570 to 590 nm), Green (495 to 570 nm), Blue (450 to 495 nm), Indigo (approx. 445 to 450 nm), Violet (380 to 445 nm). In total, these are the main colors of the visible light spectrum.
17. What are the two factors that can cause the volume of water in the ocean to change? A. Temperature and pressure B. Gravity and temperature C. Pressure and salinity level D. Salinity level and temperature
Explanation:
The density [tex]D[/tex] of the water is given by a relation between its mass [tex]m[/tex] and its volume [tex]V[/tex]:
[tex]D=\frac{m}{V}[/tex]
Isolating the volume:
[tex]V=\frac{m}{D}[/tex]
This means the volume of the water will depend on its mass and its density.
In this sense, the two factors that affect the volume of seawater are salinity level and temperature.
This is because the salinity (amount of salt in water) changes the its mass and its density, therefore its volume. The higher the salinity, the greater the volume.
In the case of temperature, when it increases, the volume of water also increases and when the temperature decreases, the volume also decreases.
Answer:
D. Salinity level and temperature
Explanation:I took the test
The Bernoulli principle states that the pressure inside a liquid increases with depth:
A. True
B. False
C. True only if the channel is horizontal
D. True only if the section of the channel is constant
E. True only if there is no friction
The answer should be B. but why?
Explanation:
According to Bernoulli's principle:
"In an ideal fluid (not viscous and without friction) that circulates through a closed conduit, the energy the fluid possesses remains constant along its path."
From there, Bernoulli deduced that the fluid pressure decreases when the flow rate increases. And this has nothing to do with depth.
To understand it better:
In a fluid that circulates through a closed conduit (a pipe for example), it contains energy in two ways:
-Kinetic energy due to its weight and speed.
-Potential energy in the form of pressure.
Now, if the system has constant flow and the total energy (kinetic + potential) is also constant, the energy is transformed every time the transverse area of the tube is modified.
It should be noted that by modifying this transverse area, the flow rate is also modified.
Therefore, as the kinetic energy increases or decreases, this change is compensated by the decrease or increase in pressure (potential energy), since the total energy of the system cannot be created or destroyed.
Suppose a rock is dropped off a cliff with an initial speed of 0 m/s. What is
the rock's speed after 3 seconds, in m/s, if it encounters no air resistance?
Answer:
29.4 m/s
Explanation:
v = at + v₀
v = (9.8 m/s²) (3 s) + 0 m/s
v = 29.4 m/s
Answer:29.4 is correct
Explanation:
A 10 kg box resting on a horizontal, frictionless surface is attached to a 6 kg
weight by a thin, light wire that passes over a pulley . The pulley has the shape of a uniform solid disc of mass 2.5 kg and diameter 0.650 m. After the system is released, calculate
(i) the tension in the wire on both sides of the pulley.
(ii) the angular acceleration of the pulley.
Answer:
T₁ = 34.1 N
T₂ = 38.4 N
α = 10.5 rad/s²
Explanation:
Sum of the forces on the box in the x direction:
∑F = ma
T₁ = m₁ a
Sum of the torques on the pulley:
∑τ = Iα
T₂ r − T₁ r = (½ mr²) α
T₂ r − T₁ r = (½ mr²) (a / r)
T₂ − T₁ = ½ ma
Sum of the forces on the weight in the y direction:
∑F = ma
T₂ − m₂ g = m₂ (-a)
T₂ = m₂ g − m₂ a
Substitute:
(m₂ g − m₂ a) − (m₁ a) = ½ ma
m₂ g = (m₁ + m₂ + ½ m) a
a = m₂ g / (m₁ + m₂ + ½ m)
Given m₁ = 10 kg, m₂ = 6 kg, and m = 2.5 kg:
a = (6) (9.81) / (10 + 6 + ½ (2.5))
a = 3.41 m/s²
Therefore:
T₁ = m₁ a
T₁ = (10) (3.41)
T₁ = 34.1 N
T₂ = m₂ g − m₂ a
T₂ = (6)(9.81) − (6)(3.41)
T₂ = 38.4 N
α = a / r
α = 3.41 / 0.325
α = 10.5 rad/s²
How are the fossils of the Precambrian eon different from the Phanerozoic eon
Answer:by carbon and oder element
Explanation:
The Precambrian eon is different from the Phanerozoic eon due to the fact that the fossil present from the Precambrian eon was of mostly microorganisms which are single cellular organisms.
Explanation:
The Phanerozoic eon was marked with eon which had the multi cellular organism that is the level of cellularity was enhanced by this eon due to the evolutionary course taken for the organisms. Phanerozoic eon and Precambrian eon had a vast difference of cellular level of organization found in the fossil remains of both times.
Precambrian eon had many primitive algae which existed mostly till the earliest Cambrian era only. Due to single cellularity of the organisms, the fossil of Precambrian eon was not much in abundance whereas the Phanerozoic eon had much abundant fossil remains.
what is the kinetic energy of a 60 kg person jogging at 2 m/s
Ek = 1/2 m v^2
Ek = 1/2 × 60 × 2^2
Ek = 1/2 × 60 × 4
Ek = 120 J
the kinectic energy is 120 J
A helicopter is hovering at an altitude of 200m above the surface of the lake. A speaker on the helicopter is sending out sound waves which are reflected from both the surface of the water and bottom of the lake. If the differences in arrival times of the two echoes is measured to be 0.24s, what is the depth of the lake? (The atmospheric temperature is 20°C)
Explanation:
The first echo travels from the helicopter to the surface and back. The second echo travels from the helicopter to the surface to the bottom of the lake and then back.
We know the difference in time is 0.24 s, so the time it takes the sound wave to travel through only the water is 0.24 s. Since the sound wave covers the distance twice (first from the surface to the bottom, then the bottom to the surface), we only want half the time, 0.12 s.
The speed of sound in water at 20°C is 1481 m/s. Therefore:
d = 1481 m/s × 0.12 s
d = 178 m
The depth of the lake is 178 meters (round as needed).
To calculate the depth of the lake, use the speed of sound at 20°C (343 m/s) and multiply it by the time difference (0.24s) between the echoes. This product gives the total distance sound traveled, which is twice the depth of the lake. The depth is found by dividing this distance by two, resulting in 41.16 meters.
Explanation:The student is asking about determining the depth of a lake using sound waves from a hovering helicopter that are reflected from the surface of the water and the bottom of the lake. The time difference between the arrivals of the two echoes is given, and the speed of sound at 20°C needs to be used in the calculations. Since the speed of sound at this temperature is approximately 343 m/s, the total distance traveled by the sound waves is the speed of sound multiplied by the time difference between the echoes. This total distance is twice the depth of the lake, because the sound travels to the lake bottom and back up. Dividing this total distance by two gives the depth of the lake.
The formula to calculate the total distance traveled by the sound is:
Total distance = Speed of sound × Time difference
To find the depth, we divide the total distance by two:
Depth = (Speed of sound × Time difference) / 2
Depth calculation:
Speed of sound at 20°C = 343 m/sTime difference = 0.24 sTotal distance = 343 m/s × 0.24 s = 82.32 m
Depth = 82.32 m / 2 = 41.16 m
The depth of the lake is therefore 41.16 meters.
Matthew drops a ball and watches it bounce back up from the ground he draws a force diagram that shows the forces when the ball collides with the grand Which diagram correctly shows the forces involved
Answer: i think that the third option is correct
the force of the ball goes to the floor making it go down and up reflecting a little lower force back to the ball and sending the ball back up
hope this helps
brainliest if possible
Answer:
Option (c)
Explanation:
In this question it is given that, Matthew drops a ball and watches it bounce back up from the ground. The force diagram is given which shows when the ball collides with the ground.
The force acting on the ball are gravitational force and drag force. According to Newton's third law of motion, the force acting on the ball are equal in magnitude but the direction is opposite.
So, diagram (c) shows the correct scenario as per third law of motion. Hence, the correct option is (c).
positional and non positional different between
Explanation:
In positional number system,
1. each symbol represents different value depending on the position they occupy in a number.
2. In positional number system, each system has a value that relates to the number directly next to it. The total value of a positional number is the total of the resultant value of all positions.
3. Example: 12 can be 1 x 10 + 2 x 1, 10 + 2= 12
whereas in Non-Positional number
1. In non-positional number system, each symbol represents the same value regardless of its position
2. In non-positional number system each symbol represents a number with its own place value.
3. Example: Roman number system where I for 1, II for 2 etc.
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