00:01
Hello, in this question we have a ball that is a drop from a height of 1 .5 meters.
00:19
And the ball bounces back to a height of 0 .45 meters.
00:34
Where we are to find its velocity right before hitting the ground and right after leaving the ground.
00:47
So the speed with which strikes the ground for this part of the motion, we know that initial velocity is zero, it falls under gravity.
00:58
So our acceleration is 9 .8.
01:02
This time to be traveled is 1 .5.
01:06
And so what is our v? so we know v squared equals u squared plus 2a.
01:16
Yes.
01:19
We don't find v as 5 .4 meters per second.
01:28
We negate it because the velocity is pointing downward.
01:31
It is moving downwards.
01:32
So we can just choose a convention where down is negative, half is positive.
01:36
For the second part, we have to find the speed v just before it leaves the ground.
01:41
So for this part of the motion, that speed is an initial.
01:45
That is an initial speed as it leaves the ground.
01:48
And at the final point, the ball will come to rest in the a...