A student bends a paper clip back and forth rapidly. After repeating this action several times, the student touches the bent part of the paper clip and observes that the metal has become warm. Which statement best explains the student's observation? Because mass is lost from the paper clip, heat energy is increased in the paper clip. Because volume is lost from the paper clip, heat energy is increased in the paper clip. Because energy is conserved, some energy of motion is converted into heat in the paper clip. Because energy is conserved, some of the motion is converted into electricity in the paper clip.​