Tracy (of mass 55 kg) and tom (of mass 75 kg) are standing at rest in the center of the roller rink, facing each other, free to move. tracy pushes off tom with her hands and remains in contact with tom’s hands, applying a constant force for 0.9 s. tracy moves 0.35 m during this time. when she stops pushing off tom, she moves at a constant speed. what is tracy’s constant acceleration during her time of contact with tom? answer in units of m/s 2 .

Sally turns on her cellular telephone to speak to her friend who is located thousands of miles away. which of the following best describes how such a telephone is able to transmit and receive information? a. the cellular telephone transmits, receives, and encodes information using only sound waves. b. the cellular telephone transmits, receives, and encodes information using only electromagnetic waves. c. the cellular telephone transmits information by electromagnetic waves to a receiver which then encodes them and produces sound. d. the cellular telephone transmits information by sound waves to a receiver which then encodes them and produces electromagnetic waves.