00:01
All right, so we have a block sliding down an incline plane that has an angle theta to it and when the block reaches the bottom it is then projected back up the plane with a speed.
00:14
We'll just call this v not we want to know how high up the ramp does it go now that could mean two things how high in this sense like what is the height h or how far up the ramp? it's a go, but i'll answer in both cases so i have the easiest way to do this is.
00:30
I'm the easiest way to do this.
00:30
I'm the height h's a height h or how far up the ramps is it go.
00:30
I'm the height h is a go.
00:30
I'm the this is with the conservation of energy, which says that the change in kinetic energy is equal to the negative change in potential energy.
00:41
So at the top of its trajectory, it has no kinetic energy.
00:45
So the change in kinetic energy is going to be negative one -half mv -not squared because the change is final minus initial value.
00:54
There's no final value.
00:55
So it's negative one -half mv squared.
00:57
And this is going to be equal to, well, our initial potential energy is zero at the bottom of the ramp.
01:03
So our final energy is going to be m .g .h.
01:07
And so we have this.
01:09
So these negative signs cancel...