1.Easy
A 1700 kg car moving at 13 m/s runs into a stationary 1100 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 = 13 m/sm2 = 1100 kgv2 = 0 m/s
v′ = m/s
Momentum & collisions worksheet with answers
2.Easy
A 6 kg rifle, free to move, fires a 15 g bullet at 350 m/s. Both start at rest. Find the recoil speed V of the rifle.
M = 6 kgm = 15 gv = 350 m/s
V = m/s
3.Medium
A 500 kg car moving at 13 m/s runs into a stationary 700 kg car and the two lock together. How much kinetic energy ΔK is lost in the collision?
m1 = 500 kgv1 = 13 m/sm2 = 700 kgv2 = 0
ΔK = J
4.Medium
A 6 kg projectile moving horizontally at 9 m/s explodes into two fragments that move along the same line. The 3 kg fragment continues forwards at 69 m/s. Find the velocity v′2 of the 3 kg fragment (positive in the original direction).
M = 6 kgu = 9 m/sm1 = 3 kgv′1 = 69 m/sm2 = 3 kg
v′2 = m/s
5.Hard
A 0.35 kg ball hits a wall at 13 m/s and bounces straight back at 5 m/s. The contact lasts 25 ms. Find the average force Favg of the wall on the ball.
m = 0.35 kgvin = 13 m/svout = 5 m/sΔt = 25 ms
Favg = N
6.Hard
A 0.55 kg ball hits a wall at 13 m/s and bounces straight back at 19 m/s. The contact lasts 20 ms. Find the average force Favg of the wall on the ball.
m = 0.55 kgvin = 13 m/svout = 19 m/sΔt = 20 ms
Favg = N
Answer key
- 1. v′ = 7.893 m/s
- 2. V = 0.875 m/s
- 3. ΔK = 24646 J
- 4. v′2 = −51 m/s
- 5. Favg = 252 N
- 6. Favg = 880 N
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