which illustrates in an increase in potential energy?

a. a firecracker explodes
b. a person climbs a set of stairs
c. a wind-up toy winding down
d. an apple dropping from a tree

try b.

The correct answer is b. a person climbs a set of stairs.

Explanation:

Potential energy is the energy that an object possesses due to its position or state. In this case, as a person climbs a set of stairs, their potential energy increases. The person's position in relation to the ground is elevated as they move higher on the stairs. As a result, their potential energy increases as well.

The correct answer is option D: an apple dropping from a tree illustrates an increase in potential energy.

To understand why the apple dropping from a tree represents an increase in potential energy, we need to understand what potential energy is. Potential energy is the energy that an object possesses due to its position or state.

In this scenario, as the apple is still on the tree, it is at a higher position relative to the ground. The apple has gravitational potential energy, which is determined by its height above the ground and its mass. As it falls from the tree, its height decreases, and therefore its potential energy decreases as well.

So, if we consider the other options:
- Option A: A firecracker exploding involves a release of stored chemical energy in the firecracker, but it does not increase potential energy.
- Option B: A person climbing a set of stairs requires the input of energy (from the person), but it only increases the person's gravitational potential energy in relation to the ground, not the overall potential energy.
- Option C: A wind-up toy winding down involves the conversion of stored mechanical energy into other forms (like sound or heat), but it does not represent an increase in potential energy.

Therefore, the correct option that illustrates an increase in potential energy is the apple dropping from a tree (option D).