10. A cube of mass m sliding on a frictionless surface at speed vo. It undergoes a perfectly elastic collision with the bottom tip of a rod of length d

and mass M= 3m. The rod is allowed to pivot on a frictionless axle through its center and is initially at rest hanging straight down. See image to the right.What is the cube's velocity - both speed and direction - directly after the collision? [5 pt]

Fig: 1

Fig: 2