Work Energy Power Review

1. Work Energy Power Review

2. Work is done when • the displacement is not zero and a force is parallel to the displacement • the displacement is zero. • the force is zero. • the force and displacement are perpendicular.

3. A 75kg man and a 55kg woman perform dives on adjacent diving boards of the same height. Which of them will have a greater kinetic energy entering the water? • The man • The woman • Both will be the same • Unable to be determined

4. A 75kg man and a 55kg woman perform dives on adjacent diving boards of the same height. Which of them will have a greater speed entering the water? • The man • The woman • Both will be the same • Unable to be determined

5. Two rescue packages of equal mass are dropped from planes of different altitude - red plane at 1500m and a blue plane at 2500m. Which of them will have a greater speed hitting land? • Red plane’s package • Blue plane’s package • Both will be the same • Unable to be determined

6. If both the mass and the height of a ball are doubled, the potential energy of the ball is increased by a factor of • 2 • ½ • 4 • 8 • 16

7. If both the mass and the velocity of a ball are tripled, the kinetic energy of the ball is increased by a factor of • 3. • 6. • 9. • 27.

8. Of the following examples, the one that represents work as defined by a scientist is: • lifting a book from your desk. • leaning on a shovel while others labor. • pushing hard against a wall for an hour. • carrying a heavy box on your head.

9. A machine that does more work than another must have moved the object is a shorter amount of time? • True • False Answer Now

10. In a closed system, what is constant? • Potential energy • Kinetic energy • Mechanical energy • All are constant Answer Now

11. Which of the following represents the rate that work is being done? • Power • Kinetic Energy • Potential Energy • Total Energy

12. A rolling wagon has 50 joules of kinetic energy. If the wagon’s velocity is doubled, the kinetic energy of the wagon: • is reduced to 25 joules. • is increased to 100 joules. • is increased to 200 joules. • remains the same.

13. A mouse and a raccoon race to the top of a tree for the last morsel of food left before winter. Both arrive at the top at the same time. Which had more power? • Mouse • Raccoon • Same • Unable to be determined

14. A linebacker pushes against the blocker but the blocker does not move. The work is: • Positive • Negative • Zero • Not enough info Answer Now

15. When doing a bench press, you gradually lower the bar down to your chest. The work done by gravity is: • Positive • Negative • Zero • Not enough info Answer Now

16. When doing a bench press, you gradually lower the bar down to your chest. The work done by your arms is: • Positive • Negative • Zero • Not enough info Answer Now

17. Because your two-year old cousin refuses to move, you pull him along the ground. The work done is: • Positive • Negative • Zero • Not enough info Answer Now