Bennett Mechanical Test Bennett Mechanical Work and Energy Questions and Answers 3

Question 1

A machine receives 800 J of input energy but delivers only 600 J of useful work. What is its efficiency?

Accepted Answer

75%

Answer

80%

Answer

70%

Answer

85%

Question 2

Which energy conversion takes place in a hydroelectric dam?

Accepted Answer

Gravitational potential to electrical

Answer

Chemical to electrical

Answer

Kinetic to thermal

Answer

Nuclear to mechanical

Question 3

If the speed of a moving object is doubled, how does its kinetic energy change?

Accepted Answer

It quadruples

Answer

It doubles

Answer

It triples

Answer

It stays the same

Question 4

A 200 N force moves an object 3 m in the direction of the force. How much work is done?

Accepted Answer

600 J

Answer

67 J

Answer

200 J

Answer

400 J

Question 5

Horsepower (hp) is a unit used to measure which physical quantity?

Accepted Answer

Power

Answer

Energy

Answer

Force

Answer

Work

Question 6

A roller coaster car at the very top of a hill has its maximum amount of which energy?

Accepted Answer

Gravitational potential energy

Answer

Kinetic energy

Answer

Thermal energy

Answer

Elastic potential energy