4. A 0.015 kg bullet is fired at a 1.5 kg block initially at rest. The bullet, moving with an initial speed of 500 m/s, emerges from the block with a speed of 400 m/s. What is the speed of the block after the collision?

1) when you rub your hands together quickly, the kinetic energy is converted to mechanical energy.2) thermal energy from the sun travels to earth as infrared waves.3) energy is transferred through the matter of space by electromagnetic waves. 4) when a match is burned, chemical potential energy is converted to thermal and radiant energy. 5) seismicwaves are caused by back and forth movement , or vibration, of an object. 6) mechanicalenergy in an engine changes thermal energy into kinetic energy to make a car move.