A roller coaster car is initially at rest at the top hill of its track. The car descends the frictionless track and acquires a speed of 10 m/s when it reaches bottom of the hill. Find the speed of the car when it is half-way down the hill?

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.

A. they hold atoms  together with a molecule.its a force that exist between molecules. hope this .