WTMA Energy, Work, and Power 4

Question 1

Water stored behind a dam is an example of which type of energy?

Accepted Answer

Gravitational potential energy

Answer

Water elevated behind a dam has gravitational potential energy due to its height above the turbines below.

Question 2

A 60-watt light bulb runs for 2 hours. How much energy does it consume?

Accepted Answer

120 watt-hours

Answer

Energy = Power × Time = 60 W × 2 h = 120 watt-hours.

Question 3

In a pulley system, a worker pulls 6 feet of rope to raise a load 2 feet. What is the mechanical advantage?

Accepted Answer

3

Answer

Mechanical advantage = effort distance / load distance = 6 / 2 = 3.

Question 4

What happens to the potential energy of a roller coaster car as it descends a hill (ignoring friction)?

Accepted Answer

It converts to kinetic energy

Answer

As the car descends, gravitational potential energy converts to kinetic energy, increasing the car's speed.

Question 5

Which of the following actions requires the most power?

Accepted Answer

Lifting 100 lbs 10 feet in 5 seconds

Answer

Power = Work/Time; 100×10/5 = 200 ft-lb/s is the highest among all choices.

WTMA - Wiesen Test of Mechanical Aptitude Practice Test