Energy and Momentum Practice — Work, Power and Collisions
10 problems · instant feedback · full explanations
Energy and momentum problems are shortcut problems: instead of tracking every force, track what is conserved. Ask first — is energy conserved here, or only momentum?
Q1.
What is the kinetic energy of a 2 kg object moving at 3 m/s?
Multiple choice · Easy
Q2.
If the speed of an object doubles, what happens to its kinetic energy?
Multiple choice · Easy
Q3.
A 1200 kg car travels at 25 m/s. What is its kinetic energy in joules?
Numerical answer (J) · Easy
Q4.
How much work is done lifting a 50 kg box vertically by 2 m at constant speed? (g = 9.8 m/s²)
Numerical answer (J) · Medium
Q5.
A 150 g tennis ball is served at 20 m/s. What is the magnitude of its momentum?
Numerical answer (kg·m/s) · Medium
Q6.
A motor does 980 J of work in 4 s. What is its power output?
Multiple choice · Medium
Q7.
True or false: you do physical work when you push hard against a wall that does not move.
True / False · Easy
Q8.
A moving billiard ball strikes an identical stationary ball head-on in a perfectly elastic collision. What happens?
Multiple choice · Hard
Q9.
A 5 kg rock falls from rest from a 10 m cliff. What is its speed just before hitting the ground? Ignore air resistance. (g = 9.8 m/s²)
Numerical answer (m/s) · Hard
Q10.
True or false: total momentum is conserved in an inelastic collision.
True / False · Medium