An object initially at rest explodes in two fragments of masses 4.3 kg and 1.6 kg that move in opposite directions. If the speed of the first fragment is 8.4 m/s, find the internal energy of the explosion.

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.