Two blocks are initially stationary on a frictionless horizontal surface. One is wooden and the other is steel. A steel ball is launched horizontally at speed $v$ towards the wooden block. The ball becomes embedded in the block, so after the impact the ball and block travel together. A second identical steel ball is launched horizontally at speed $v$ towards the steel block. This steel ball then bounces back along its original line of motion with speed $\frac{v}{2}$. The wooden block and the steel block have the same mass. Which statement about the blocks immediately after the collisions is correct?
- ABoth blocks must travel with the same speed.
- BThe steel block must travel faster than the wooden block.
- CThe wooden block must travel faster than the steel block.
- DThe masses of the blocks and the steel ball are needed to determine which block travels faster.