Eddie tosses his phone up to his friend's window, which is 4 m above the ground. What energy conversion takes place with respect
to the phone? A. Kinetic energy to elastic potential energy
B. Gravitational potential energy to kinetic energy
C. Elastic potential energy to kinetic energy
D. Kinetic energy to gravitational potential energy
D. Kinetic energy to gravitational potential energy.
Explanation:
Conservation of energy principle states that the total energy of a system remains constant
When the phone is being thrown from the ground, it has maximum kinetic energy and zero potential energy since the phone will go up only if it is given some initial velocity. As it moves up, this kinetic energy decreases and potential energy increases, the total energy remaining constant. At the 4 m height of the window, the maximum kinetic energy is totally converted entirely to gravitational potential energy.
According to the plot, the positions at time <em>t</em> = 0 s and <em>t</em> = 19 s are -1 m and -2 m, respectively. So the average velocity for the 19-s interval is
