Question

Two people observe a leaf falling from a tree. One person is standing on a ladder and the other is on the ground. If each person were to compare the energy of the leaf observed, would each person find the following to be the same or different for the leaf, from the point where it falls off the tree to when it hits the ground: (a) the kinetic energy of the leaf; (b) the change in gravitational potential energy; (c) the final gravitational potential energy?

a) Different for all three parameters.
b) The same for all three parameters.
c) Different only for kinetic energy.
d) Different only for change in gravitational potential energy.

Answer 1

Each person would find the kinetic energy, change in gravitational potential energy, and final gravitational potential energy of the falling leaf to be different based on their height above the ground.

Step-by-step explanation:

Each person would find the following to be different for the leaf:

1. The kinetic energy of the leaf
2. The change in gravitational potential energy
3. The final gravitational potential energy

Let's break it down:

1. While falling, the leaf gathers speed and its kinetic energy increases. Since the ladder person is higher up than the ground person, they would observe a higher initial potential energy and hence a higher final kinetic energy compared to the ground person.
2. The change in gravitational potential energy would be different for each person because it depends on the difference in height between the starting and ending points. The ladder person would have a larger change in gravitational potential energy since they are higher above the ground.
3. Similarly, the final gravitational potential energy would be different for each person due to their different heights above the ground.

Therefore, the answer is (a) Different for all three parameters.