Question

a skateboarder heads down a smooth, steep course. what graph illustrates the change in kinetic and potential energy during this process?
a a
b b
c c
d d
(graphs: a, b, c, d with energy vs time axes; kinetic energy = solid line, potential energy = dashed line)

Explanation:

When a skateboarder goes down a smooth, steep course, potential energy (due to height) decreases as kinetic energy (due to motion) increases, assuming no energy loss (smooth course). In graph D, the dashed line (potential energy) decreases and the solid line (kinetic energy) increases, which matches the energy transformation (potential to kinetic). Graphs A and B show constant energy, which is incorrect. Graph C has potential energy increasing and kinetic energy increasing, which is wrong as potential energy should decrease.

Answer:

D. D