It depends on the direction in which the shell is launched. The time can be anything from 3.6 seconds to never.
Answer:
The solved problem is in the photo. Hope it helps.
Answer:
You're four sentences should include about how the roller coaster has the most potential energy at the top of the track, and the opposing energy, "kinetic" has the most kinetic energy when going down the hill.
Explanation:
Kinetic - In-Motion.
Potential - Gathering Energy to go into Motion.
( I'll try to answer questions to clear up confusion. )