25 questions
The given graph shows the releation between gravitional potential energy & height . If the mechanical energy at height A= 0.49 what is the kinetic energy
0.10 j
0.01 j
0.5 j
0.49 j
A ball is projected into the air. Where is potential energy the greatest?
As a roller coaster goes downhill
kinetic energy is converted into potential energy.
potential energy is converted into kinetic energy.
electrical energy is converted into potential energy.
potential energy is converted into electrical energy.
A drawn bow possesses mechanical energy in the form of _______________. After the arrow is released, the energy is transformed into _________________.
potential energy; mechanical energy
elastic potential energy; kinetic energy
gravitational potential energy; kinetic energy
elastic kinetic energy; mechanical kinetic energy
In the figure, potential energy is being converted into kinetic energy from
point A to point B
point B to point C
The only energy involved here is kinetic.
Energy is not being converted.
A pole vaulter runs forward, plants his pole, rises in the air and lands. What point represents his greatest amount of gravitational potential energy?
when he initially lands
as he runs forward to plant the pole
just before he starts to fall to the ground
after take-off as the pole expands and lifts the vaulter toward the bar
There are three shelves in a closet. The first one is 1.5 meters above the floor, the second shelf is 2.0 meters above the floor, and the third shelf is 2.5 meters above the floor.
A 10 kg box rests on the first shelf. How much gravitational potential energy does the box have relative to the second shelf?
50 J
100 J
150 J
200 J
There are three shelves in a closet. The first one is 1.5 meters above the floor, the second shelf is 2.0 meters above the floor, and the third shelf is 2.5 meters above the floor.
The box is lifted to the third shelf. How much gravitational potential energy does the box have relative to the first shelf?
100 J
50 J
-50 J
150 J
A roller coaster uses a motor to take a car to the top of its first hill. The roller coaster then travels down a 35 meter hill and to the top of the next hill. It travels with a speed of 15 m/s at the top of the second hill.
How high is the second hill? Assume no energy is lost to friction and the coaster starts from rest at the top of the first hill.
12.5 m
24 m
34 m
This cannot be determined without the mass of the car.
In July 1971, Apollo 15 astronaut Dave Scott performed an experiment on the Moon. Scott held a feather and a hammer at the same height, and let them drop at exactly the same time. Both fell at the same rate and hit the ground at the same time.
At which time did the feather have the greatest kinetic energy?
time 1
time 2
time 3
both times 1 and 3
In July 1971, Apollo 15 astronaut Dave Scott performed an experiment on the Moon. Scott held a feather and a hammer at the same height, and let them drop at exactly the same time. Both fell at the same rate and hit the ground at the same time.
At which time did the hammer have the greatest gravitational potential energy?
time 1
time 3
times 1 and 3
time 2
In July 1971, Apollo 15 astronaut Dave Scott performed an experiment on the Moon. Scott held a feather and a hammer at the same height, and let them drop at exactly the same time. Both fell at the same rate and hit the ground at the same time.
Which of the following is true about the relationship between the gravitational potential energy and the kinetic energy of the hammer?
The kinetic energy + gravitational potential energy stays the same at all times.
The kinetic energy and potential energy are the same as each other at all times.
The kinetic energy at time 1 is equal to the gravitational potential energy at time 1.
The kinetic energy at time 3 is equal to the gravitational potential energy at time 3.
An apartment building has two floors and a basement. The floors are 3.5 meters apart and the basement is 2.5 meters underground as shown.
A 100 kg man enters the apartment building at the ground floor and walks up to his second floor apartment. How much gravitational potential energy does he have relative to the ground? Use g = 10 m/s2.
350 J
700 J
3500 J
7000 J
An apartment building has two floors and a basement. The floors are 3.5 meters apart and the basement is 2.5 meters underground as shown.
The man’s 50 kg son is in the basement doing laundry. How much gravitational potential energy does the son have relative to his father on the second floor? Use g = 10 m/s2.
-3000 J
-300 J
300 J
3000 J
A crate slides down a 5-meter-long, 2-meter-high ramp as shown.
Alli places the 35 kg crate at an undesignated height and lets it slide to the bottom. Her lab partner measures the speed at the bottom of the ramp to be 5.5 m/s. Assuming the ramp is frictionless, at what height did Alli release the crate? Use g = 10 m/s2.
1.5 m
2.0 m
0.5 m
1.0 m
A temporary ladder can be used to escape from an upper story window in case of fire. The diagram shows a temporary ladder hanging from a second floor window and descending to a deck below. The ladder has 8 steps, each of which is 0.5 meters high. The surface of the deck is 1.0 meters above the ground.
A 10 kg cat is three steps below the window. What is its gravitational potential energy relative to the ground? Use g = 10 m/s2.
-350 J
-150 J
350 J
150 J
A temporary ladder can be used to escape from an upper story window in case of fire. The diagram shows a temporary ladder hanging from a second floor window and descending to a deck below. The ladder has 8 steps, each of which is 0.5 meters high. The surface of the deck is 1.0 meters above the ground.
A 50 kg dog is on the deck. What is its gravitational potential energy relative to the window? Use g = 10 m/s2.
-2000 J
-500 J
500 J
2000 J
A construction worker dropped a cement block from an undesignated height. The block had a speed of 30.0 m/s when it hit the ground. Assuming that no forces other than gravity acted on the block as it fell, from what height was the block dropped? Use g = 10 m/s2.
45 m
90 m
450 m
The height cannot be calculated without knowing the mass.
A 1,000-kg car is driving down the road at 5 m/s. The driver increases the speed of the car to 10 m/s. What is the correct amount of the increase in the kinetic energy of the car?
12,500 J
50,000 J
37,500 J
25,000 J
The Great American Soapbox Derby is an annual summer event in Akron. Soapbox cars have no engines. They roll down the hill due to the force of gravity. Use the diagram of the derby car and track to answer the question. Assume no energy loss due to friction.
At which point will the kinetic energy be the same as the gravitational potential energy of the soapbox car as it rolls down the incline?
point 1, because the car is highest
point 3, because it is still moving down the ramp
between points 2 and 3, when it is halfway down the ramp
point 4, because it will have the greatest speed