# PE/KE Questions?

1. If a ball is tossed in the air, without assuming freefall, what is the change in the rate of PE compared to the rate of KE?

2. If a ball was thrown on the moon, without atmosphere, what is the change in the rate of PE compared to the rate of KE?

Question answers are the same for both:

1. P/t is equal in magnitude and equal in sign to K/t

2 P/t is smaller than K/t

3. P/t is equal in magnitude but not in sign to ΔK/Δt

4. P/t is larger than K/t

### 1 Answer

- ArgentLv 74 weeks ago
In each case, the rate of conversion of KE to PE (or PE to KE) is the same. (It wouldn't make sense otherwise, to have some KE (or PE) left over when the PE (or KE) was maximum or minimum.

So the answer is #3, because ΔK/ΔT is equal to ΔP/ΔT but opposite in sign. When one increases (positive change), the other decreases (negative change).