BMST Work, Energy, and Power

Question 1

How much work is done when a force of 50 N moves an object 8 meters in the direction of the force?

Accepted Answer

400 J

Answer

Work = Force × Distance = 50 N × 8 m = 400 Joules. Work is only done when the force has a component in the direction of motion.

Question 2

A 2 kg ball is moving at 6 m/s. What is its kinetic energy?

Accepted Answer

36 J

Answer

Kinetic Energy = ½mv² = ½ × 2 × (6)² = ½ × 2 × 36 = 36 J.

Question 3

An object with a mass of 5 kg is lifted 3 meters above the ground. What is its gravitational potential energy? (g = 10 m/s²)

Accepted Answer

150 J

Answer

Potential Energy = mgh = 5 kg × 10 m/s² × 3 m = 150 J.

Question 4

A machine does 500 J of work in 10 seconds. What is its power output?

Accepted Answer

50 W

Answer

Power = Work / Time = 500 J / 10 s = 50 Watts. Power measures the rate at which work is done.

Question 5

According to the work-energy theorem, if a net force does 200 J of work on an object, what happens to the object's kinetic energy?

Accepted Answer

It increases by 200 J

Answer

The work-energy theorem states that net work done on an object equals the change in its kinetic energy. Positive net work increases kinetic energy.

BMST - Basic Math and Science Test Practice Test