1.Easy
A 900 kg car moving at 22 m/s runs into a stationary 1200 kg car. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).
m1 = 900 kgv1 = 22 m/sm2 = 1200 kgv2 = 0 m/s
v′ = m/s
Momentum & collisions worksheet with answers
2.Easy
A 700 kg car moving at 22 m/s runs into a stationary 1600 kg car. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).
m1 = 700 kgv1 = 22 m/sm2 = 1600 kgv2 = 0 m/s
v′ = m/s
3.Medium
A 19 kg projectile moving horizontally at 15 m/s explodes into two fragments that move along the same line. The 9 kg fragment continues forwards at 33 m/s. Find the velocity v′2 of the 10 kg fragment (positive in the original direction).
M = 19 kgu = 15 m/sm1 = 9 kgv′1 = 33 m/sm2 = 10 kg
v′2 = m/s
4.Medium
A 20 g bullet is fired horizontally into a 1.5 kg wooden block hanging on light strings, and stays inside it. The block swings up until it is 5 cm higher than at the start. Use g = 9.81 m/s². Find the speed v of the bullet before impact.
m = 20 gM = 1.5 kgh = 5 cmg = 9.81 m/s²
v = m/s
5.Hard
An 800 kg car runs into a parked 2000 kg car. The wrecks lock together and skid 12 m before stopping. The coefficient of kinetic friction between tyres and road is 0.6. Use g = 9.81 m/s². Find the speed v1 of the first car just before the collision.
m1 = 800 kgm2 = 2000 kgd = 12 mμ = 0.6g = 9.81 m/s²
v1 = m/s
6.Hard
A 12 g bullet is fired horizontally into a 2.5 kg block hanging from light strings 1.1 m long, and stays in it. The strings swing out to a largest angle of 30° from the vertical. Use g = 9.81 m/s². Find the speed v of the bullet before impact.
m = 12 gM = 2.5 kgL = 1.1 mθ = 30°g = 9.81 m/s²
v = m/s
Answer key
- 1. v′ = 9.429 m/s
- 2. v′ = 6.696 m/s
- 3. v′2 = −1.2 m/s
- 4. v = 75.27 m/s
- 5. v1 = 41.6 m/s
- 6. v = 356 m/s
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