college physics
three carts of masses 4.0kg, 10kg, and 3.0kg move on a frictionless horizontal track with speeds of 5.0m/s, 3.0m/s, and 4.0m/s. The carts stick together after colliding. find the velocity of the three carts.
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Answers
The velocity of the three carts after the collision is the same and equal to 4 m/s. This is because momentum is conserved in a collision. The momentum of the carts before the collision was equal to 4.0kg × 5.0m/s + 10kg × 3.0m/s + 3.0kg × 4.0m/s = 70 kgm/s. After the collision, the momentum of the combination of carts is still 70 kgm/s, but the mass is 17 kg, so the momentum is equal to 70 kgm/s/17 kg = 4 m/s. Therefore, the velocity of the three carts after the collision is 4 m/s.
