A book weighing 18.0 N is lifted from the floor and placed on a shelf 1.5 m high. What is the minimum amount of work required to accomplish this task?
What is 27 J
100
Where on a hill is a biker's kinetic energy closest to 0 J?
The top
100
What is the momentum of a 0.01 kg bullet moving at 100 m/s?
1 kgm/s
100
An egg falls and cracks on the ground. What type of collision is this?
Inelastic
100
What is the power rating of a lightbulb that uses 3,600 J of energy in 60 sec?
60 W
200
A rock climber weighs 550 N and is carrying a backpack that weighs 50 N. How much total work has been done after she climbs 12 m?
7200 J
200
A ball is thrown straight upward. The ball’s initial speed is 30 m/s and its mass is 0.05 kg, resulting in an initial kinetic energy of 22.5 J.If the initial potential energy of the ball is 10 J and there is no frictional force, what would be the ball’s total energy while it is moving?
32.5 J
200
What is the magnitude of the momentum of a 0.15 kg baseball moving at 25 m/s?
3.8 kgm/s
200
A driver loses control of his car and hits a tree. What type of collision is this?
Inelastic
200
If 100,000 J of work is done in 1000 s, what is the average power consumption in watts?
1000 W
300
Which of the following is the best example of work being done on an object?
A. holding a 50 kg barbell
B. lifting a bag of groceries
C. keeping a board in place
D. pushing on a car that will not move
B
300
A 5 kg rock and a 10 kg rock are dropped from a height of 10 m. Which loses more PE and why?
The 10kg rock, because it has more mass.
300
Which of the following has the greatest momentum?
A. 0.2 kg ball moving at 40 m/s
B. 500 kg car traveling at 16 m/s
C. 2000 kg truck traveling at 9 m/s
D. 50 kg child skateboarding at 4 m/s
C
300
At an amusement park, bumper car X moves at a speed of 2.5 m/s toward car Y, which is at rest. Describe how each of the car's momentums change after the collision.
X's momentum decreases, Y's increases, total stays the same.
300
Four students of different weights timed themselves walking up a set of stairs. Which student used the most power while walking up the stairs? (#9 from the packet)
Student W
400
Work is performed on an object by raising it 2 m above the floor. What type of energy must change in this situation?
Potential Energy
400
Describe the change in energy of a diver who falls downward toward a swimming pool. (KE, PE, and total E)
KE increases, PE decreases, total E stays the same.
400
A dog running at 5 m/s has a momentum of 250 kgm/s. What is the dog's mass?
50 kg
400
Two toy carts collide. Cart 1 has a mass of 15 kg and is moving right at a speed of 2 m/s. Cart 2 has a mass of 5 kg and is NOT moving. When they collide, the carts will stick together. Neglecting friction, what will be the velocity of the carts after the collision? Include a direction!!
1.5 m/s right
400
In a competition, weightlifter 1 lifts a 100 kg weight from the floor. Weightlifter 2 also lifts a 100 kg weight to the same height above the floor, but takes a longer time to do so. Compare the amounts of work and power they use.
Same work; Weightlifter 2 uses less power.
500
A man applies a force of 100 N to a rock for 60 seconds, but the rock does not move. What is the amount of work done by the man on the rock?
0 J
500
The potential energy of a 77 kg diver standing on a 20 m high diving tower is 15,400 J. Two-thirds of the way down during the dive into the pool, his potential energy is 5,100 J.Neglecting air resistance, what is the diver’s kinetic energy at this point?
10,300 J
500
An object with a mass of 3 kg has a momentum of 75 kg • m/s. What is its velocity?
25 m/s
500
A car suddenly explodes into two pieces. The piece to the left has a mass of 50 kg and moves with a velocity of 3 m/s. The piece to the right has a mass of 15 kg. What is its velocity?
10 m/s
500
A person is using a force of 200 N to push a box. How much power does the person need to push the box a distance of 4 m in 10 s?