1.Easy
A 0.5 kg ball at rest is kicked. The foot pushes it with an average force of 300 N for 15 ms. Find the speed v of the ball just after the kick.
m = 0.5 kgFavg = 300 NΔt = 15 ms
v = m/s
Momentum & collisions worksheet with answers
2.Easy
A 1700 kg car moving at 20 m/s runs into a stationary 1900 kg car. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).
m1 = 1700 kgv1 = 20 m/sm2 = 1900 kgv2 = 0 m/s
v′ = m/s
3.Medium
A 5 kg projectile moving horizontally at 15 m/s explodes into two fragments that move along the same line. The 2 kg fragment continues forwards at 33 m/s. Find the velocity v′2 of the 3 kg fragment (positive in the original direction).
M = 5 kgu = 15 m/sm1 = 2 kgv′1 = 33 m/sm2 = 3 kg
v′2 = m/s
4.Medium
A 5 kg projectile moving horizontally at 36 m/s explodes into two fragments that move along the same line. The 3 kg fragment continues forwards at 46 m/s. Find the velocity v′2 of the 2 kg fragment (positive in the original direction).
M = 5 kgu = 36 m/sm1 = 3 kgv′1 = 46 m/sm2 = 2 kg
v′2 = m/s
5.Hard
A 0.15 kg ball hits a wall at 30 m/s and bounces straight back at 15 m/s. The contact lasts 20 ms. Find the magnitude of the impulse J the wall gives the ball.
m = 0.15 kgvin = 30 m/svout = 15 m/sΔt = 20 ms
J = N·s
6.Hard
A 0.25 kg ball hits a wall at 20 m/s and bounces straight back at 5 m/s. The contact lasts 5 ms. Find the magnitude of the impulse J the wall gives the ball.
m = 0.25 kgvin = 20 m/svout = 5 m/sΔt = 5 ms
J = N·s
Answer key
- 1. v = 9 m/s
- 2. v′ = 9.444 m/s
- 3. v′2 = 3 m/s
- 4. v′2 = 21 m/s
- 5. J = 6.75 N·s
- 6. J = 6.25 N·s
Full step-by-step solutions: practise this topic on examproblems.com.