1.Easy
A 1300 kg car moving at 20 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 = 1300 kgv1 = 20 m/sm2 = 1600 kgv2 = 0 m/s
v′ = m/s
Momentum & collisions worksheet with answers
2.Easy
A 1900 kg car moving at 21 m/s runs into a stationary 1400 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 = 21 m/sm2 = 1400 kgv2 = 0 m/s
v′ = m/s
3.Medium
A 19 kg projectile moving horizontally at 21 m/s explodes into two fragments that move along the same line. The 3 kg fragment continues forwards at 67 m/s. Find the velocity v′2 of the 16 kg fragment (positive in the original direction).
M = 19 kgu = 21 m/sm1 = 3 kgv′1 = 67 m/sm2 = 16 kg
v′2 = m/s
4.Medium
A 12 g bullet is fired horizontally into a 3.5 kg wooden block hanging on light strings, and stays inside it. The block swings up until it is 12 cm higher than at the start. Use g = 9.81 m/s². Find the speed v of the bullet before impact.
m = 12 gM = 3.5 kgh = 12 cmg = 9.81 m/s²
v = m/s
5.Hard
A 0.35 kg ball hits a wall at 21 m/s and bounces straight back at 12 m/s. The contact lasts 10 ms. Find the magnitude of the impulse J the wall gives the ball.
m = 0.35 kgvin = 21 m/svout = 12 m/sΔt = 10 ms
J = N·s
6.Hard
At a crossing a 900 kg car travelling east at 12 m/s collides with a 1100 kg car travelling north at 23 m/s. The cars lock together. Find the direction θ of the wreck just after the collision, measured north of east.
m1 = 900 kgv1 = 12 m/s (E)m2 = 1100 kgv2 = 23 m/s (N)
θ = °
Answer key
- 1. v′ = 8.966 m/s
- 2. v′ = 12.09 m/s
- 3. v′2 = 12.38 m/s
- 4. v = 449.1 m/s
- 5. J = 11.55 N·s
- 6. θ = 66.88 °
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