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15 questions
Suppose a cart has a kinetic energy of 0.5 J. If you add enough mass to double the mass and make the cart go three times as fast, its kinetic energy is now ---.
6 J
3 J
18 J
9 J
Two equal mass marbles are at the top of a ramp. One marble falls to the ground off the back while the other rolls down the ramp. What is true about the marbles when they reach the ground?
The marble that rolled down the ramp is moving faster than the marble that fell.
The marble that fell down the back of the ramp is moving faster than the marble that rolled.
The marble that rolled down the ramp is not moving when it reaches the ground.
The two marbles are moving with the same speed.
A crane lifts an 8-m long steel girder weighing 2600 N up 15 m off the ground. The crane did ___ of work.
0 J
39000 J
20800 J
2600 J
A crane carries an 8-m long steel girder weighing 2600 N out 12 m to the end of the crane. The crane did ___ of work.
0 J
2600 J
20800 J
31200 J
Potential energy is associated with ---.
speed
position
direction
temperature
Kinetic energy is associated with ---.
speed
position
direction
temperature
A block starts at rest at point P at the top of a ramp which is height h above the ground. The block slides down one side and up the other, stopping at a point less than h above the ground.
The block did not go as high on the other side because gravity pulls down.
The block did not go as high on the other side because potential energy always has to decrease.
The block did not go as high on the other side because work from friction made the mechanical energy less.
The situation as described is impossible to happen.
If there is no friction on this track, at which point would the coaster have the most kinetic energy?
A
B
C
D
Where is the roller coaster gaining potential energy?
A to B
B to C
C to D
The roller coaster is always losing potential energy
A 40-kg person is climbing 3 m up a flight of stairs in 6 seconds. How much work did they do climbing the stairs?
400 J
1200 J
200 J
120 J
A 40-kg person is climbing 3 m up a flight of stairs in 6 seconds. How much power did they exert climbing the stairs?
400 W
1200 W
200 W
120 W
How high up is a 3200-kg plane if it has 960000 J of potential energy?
10 m
30 m
307200000 m
300 m
What effect do external forces like an applied force, friction force, or drag force have?
They have no effect on a system's mechanical energy.
They convert kinetic energy into potential energy.
They convert potential energy into kinetic energy.
They convert between mechanical energy and other forms of energy to change the total mechanical energy of the system.
If a 1300-kg car has been lifted so it has 19500 J of potential energy, it was lifted up ---.
1.5 m
150 m
15 m
0.67 m
How does conservation of energy explain why something that is falling should speed up?
It gains kinetic energy because it gains potential energy.
It loses kinetic energy because no work was done on it.
It gains kinetic energy because it loses potential energy.
It loses kinetic energy because the Earth gains potential energy.