00:01
Questions about falling stones in a cliff.
00:03
So in the first question, we have to calculate the velocity of the stone when it strikes the ground.
00:11
So we're going to use an energy conservation principle.
00:15
At the top point, the stone had only potential energy, mgh, but at the bottom, this potential energy was converted into kinetic energy.
00:25
Therefore, mgh equals to mb squared over two, and then velocity.
00:30
Equals to square root of 2gh.
00:32
So here we can replace g and h with numbers.
00:36
And at the end of the day, we get that it's 71 .4 meters per second...