A 1-kg chunk of putty moving at 1 m/s collides with and sticks to a 5-kg bowling ball that is initially at rest on a frictionless surface. The speed of the putty thereafter is

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Quizplus · Accepted Answer

The speed of the putty and the bowling ball after the collision can be found using the principle of conservation of momentum. Before the collision, the total momentum is the momentum of the putty since the bowling ball is at rest. The momentum of the putty is its mass times its velocity, which is $1\, \text{kg} \times 1\, \text{m/s} = 1\, \text{kg}\cdot\text{m/s}$. After the collision, the putty and the bowling ball stick together and move as one object with a combined mass of $1\, \text{kg} + 5\, \text{kg} = 6\, \text{kg}$. To conserve momentum, the total momentum before the collision must equal the total momentum after the collision. Thus, $1\, \text{kg}\cdot\text{m/s} = 6\, \text{kg} \times v$, where $v$ is the velocity of the combined mass after the collision. Solving for $v$ gives $v = 1/6\, \text{m/s}$.

A 1-Kg Chunk of Putty Moving at 1 M/s Collides