Answer:
<em>Answer: D. Only R</em>
Explanation:
<u>The Principle Of Conservation Of Mechanical Energy</u>
In the absence of friction, the total mechanical energy is conserved. That means that
Em=U+K is constant, being U the potential energy and K the kinetic energy.
At the top of the path (point Q), Joshua is at rest but his height is at a maximum. Thus his kinetic energy is zero.
At point P, Joshua is at the minimum level (potential energy zero) and his speed is at a maximum.
At point R, Joshua has some height and some speed which means he has both types of energy.
Answer: D. Only R
