Physics Work and Energy Quiz

An object is lifted with a force of 40 N over a distance of 2 m. How much work is done?

• 20 J

• 40 J

• 60 J

• 80 J

The kinetic energy of a 3 kg object moving at 4 m/s is:

• 8 J

• 12 J

• 24 J

• 48 J

A 2 kg object falls from a height of 5 m. What is its potential energy at the top? (Use g = 9.8 m/s²)

• 19.6 J

• 49 J

• 98 J

• 196 J

A car accelerates from rest to 20 m/s in 4 seconds. What is its acceleration?

• 4 m/s²

• 5 m/s²

• 8 m/s²

• 10 m/s²

If two objects with masses 2 kg and 4 kg are 1 m apart, what is the gravitational force between them? (Use $ G = 6.67 \times 10^{-11} \, \text{Nm}^2/\text{kg}^2$)

• A) $ 6.67 \times 10^{-10} \, \text{N} $

• B) $ 1.67 \times 10^{-10} \, \text{N} $

• C) $ 3.34 \times 10^{-10} \, \text{N} $

• D) $ 6.67 \times 10^{-11} \, \text{N} $

A 0.1 kg object is dropped and gains speed as it falls due to gravity. What is the net force on the object during the fall?

• A) 0 N

• B) 0.98 N

• C) 9.8 N

• D) 98 N

What is the power if 300 J of work is done in 5 seconds?

• A) 15 W

• B) 30 W

• C) 60 W

• D) 75 W

A machine uses 1000 W of power in 10 seconds. How much energy does it use?

• A) 100 J

• B) 1000 J

• C) 5000 J

• D) 10,000 J

If 500 J of work is done on an object and its kinetic energy increases by 400 J, what happened to the remaining energy?

• Converted to potential energy

• Lost as heat or sound

• Stored as momentum

• None of the above

An electric motor does 800 J of work in 20 seconds. What is its power output?

• 20 W

• 40 W

• 60 W

• 80 W