Randall D. Knight — Rotation of a Rigid Body: Problem 82

FIGURE P12.82 shows a cube of mass \(m\) sliding without friction at speed \(v_0\). It undergoes a perfectly elastic collision with the bottom tip of a rod of length \(d\) and mass \(M = 2m\). The rod is pivoted about a frictionless axle through its center, and initially it hangs straight down and is at rest. What is the cube’s velocity—both speed and direction—after the collision?