Question

question 20 of 20
a ball is dropped from the top of a building. as it falls, what happens to its energy? (1 point)
a. kinetic energy decreases while potential energy increases
b. both kinetic and potential energy decrease
c. gravitational potential energy converts into kinetic energy
d. mechanical energy is destroyed

Explanation:

• Option A: When a ball falls, its speed increases (so kinetic energy should increase) and height decreases (so potential energy should decrease), so A is wrong.
• Option B: Kinetic energy increases as speed increases, and potential energy decreases as height decreases, so B is wrong.
• Option C: Gravity pulls the ball down, so the gravitational potential energy (due to height) converts into kinetic energy (due to motion) as the ball falls, which is correct.
• Option D: Mechanical energy (sum of kinetic and potential) is conserved in the absence of non - conservative forces (like air resistance, which is often neglected in such basic problems), so energy is not destroyed, D is wrong.

Answer:

C. Gravitational potential energy converts into kinetic energy