1.Easy
A 900 kg car moving at 17 m/s runs into a stationary 1800 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 = 17 m/sm2 = 1800 kgv2 = 0 m/s
v′ = m/s
Momentum & collisions worksheet with answers
2.Easy
A 1900 kg car moving at 14 m/s runs into a stationary 800 kg car. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).
m1 = 1900 kgv1 = 14 m/sm2 = 800 kgv2 = 0 m/s
v′ = m/s
3.Medium
A 10 g bullet is fired horizontally into a 5 kg wooden block hanging on light strings, and stays inside it. The block swings up until it is 15 cm higher than at the start. Use g = 9.81 m/s². Find the speed v of the bullet before impact.
m = 10 gM = 5 kgh = 15 cmg = 9.81 m/s²
v = m/s
4.Medium
A 4.5 kg glider moving at 3 m/s makes a perfectly elastic head-on collision with a 3.5 kg glider at rest on a frictionless track. Find the velocity v′2 of the second glider after the collision.
m1 = 4.5 kgm2 = 3.5 kgv1 = 3 m/sv2 = 0
v′2 = m/s
5.Hard
A 2000 kg car runs into a parked 800 kg car. The wrecks lock together and skid 15.5 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 = 2000 kgm2 = 800 kgd = 15.5 mμ = 0.6g = 9.81 m/s²
v1 = m/s
6.Hard
A 20 g bullet is fired horizontally into a 4.5 kg block hanging from light strings 1.9 m long, and stays in it. The strings swing out to a largest angle of 40° from the vertical. Use g = 9.81 m/s². Find the speed v of the bullet before impact.
m = 20 gM = 4.5 kgL = 1.9 mθ = 40°g = 9.81 m/s²
v = m/s
Answer key
- 1. v′ = 5.667 m/s
- 2. v′ = 9.852 m/s
- 3. v = 859.5 m/s
- 4. v′2 = 3.375 m/s
- 5. v1 = 18.91 m/s
- 6. v = 667.4 m/s
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