A box of mass 4.8 kg slides on a horizontal frictionless table and collides with another box of mass 3.0 kg, which is initially at rest at the edge of the table. The speed of the 4.8 kg box before collision is 4.0 ms−1, and the height of the table is 0.80 m. If the two boxes stick together after colliding, what is their kinetic energy at the instant just before they strike the floor?

A box of mass 4.8 kg slides on a horizontal frictionless table and collides with another box of mass 3.0 kg, which is initially at rest at the edge of the table. The speed of the 4.8 kg box before collision is 4.0 ms−1, and the height of the table is 0.80 m. If the two boxes stick together after colliding, what is their kinetic energy at the instant just before they strike the floor?