A loudspeaker contains an electromagnet that switches on and off very rapidly. This causes the cone of the speaker to move forwards and backwards very quickly. Use this information and your knowledge of sound to explain why you are able to hear the sound from the sound from a loudspeaker. *

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.