1.Easy
A 700 kg car moving at 10 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 = 700 kgv1 = 10 m/sm2 = 800 kgv2 = 0 m/s
v′ = m/s
Momentum & collisions worksheet with answers
2.Easy
A 0.3 kg ball at rest is kicked. The foot pushes it with an average force of 550 N for 8 ms. Find the speed v of the ball just after the kick.
m = 0.3 kgFavg = 550 NΔt = 8 ms
v = m/s
3.Medium
A 3.5 kg glider moving at 11 m/s makes a perfectly elastic head-on collision with a 5 kg glider at rest on a frictionless track. Find the velocity v′1 of the first glider after the collision (positive in its original direction).
m1 = 3.5 kgm2 = 5 kgv1 = 11 m/sv2 = 0
v′1 = m/s
4.Medium
A 13 kg projectile moving horizontally at 22 m/s explodes into two fragments that move along the same line. The 11 kg fragment continues forwards at 33 m/s. Find the velocity v′2 of the 2 kg fragment (positive in the original direction).
M = 13 kgu = 22 m/sm1 = 11 kgv′1 = 33 m/sm2 = 2 kg
v′2 = m/s
5.Hard
A 0.25 kg ball hits a wall at 24 m/s and bounces straight back at 6 m/s. The contact lasts 50 ms. Find the magnitude of the impulse J the wall gives the ball.
m = 0.25 kgvin = 24 m/svout = 6 m/sΔt = 50 ms
J = N·s
6.Hard
A 0.45 kg ball hits a wall at 16 m/s and bounces straight back at 20 m/s. The contact lasts 50 ms. Find the magnitude of the impulse J the wall gives the ball.
m = 0.45 kgvin = 16 m/svout = 20 m/sΔt = 50 ms
J = N·s
Answer key
- 1. v′ = 4.667 m/s
- 2. v = 14.67 m/s
- 3. v′1 = −1.941 m/s
- 4. v′2 = −38.5 m/s
- 5. J = 7.5 N·s
- 6. J = 16.2 N·s
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