00:01
Okay, for this scenario, you've got an object and it's located in the branches of a tree.
00:09
That's a tree.
00:11
And that object is located at a height of 16 meters, which is actually quite a long ways up.
00:23
And you realize or you determine for some reason that if you could hit that object at 5 meters per second, you'll be able to dislodge it.
00:34
And so the question's going to be, you know, one, how fast you need to throw it? is the second question.
00:40
The first question is, does the speed that you throw it depend on the angle, which is to say if you're throwing it from directly underneath, do you have to throw it faster or slower than if you throw it from over here at an angle? so let's go ahead and set up the scenario that we're going to get to.
00:58
You've got an object here, and it's at a height, of 16 meters above the ground, you start by launching at a height of two meters above the ground.
01:11
And you can either throw it directly from the bottom, or let's just pick some kind of an angle.
01:16
And we can even do a third one at a shallower angle.
01:19
And all of those are launched at two meters above the ground, and all of them climb to a height of 16 meters, and all of them want to reach five meters per second when they get to the target.
01:32
And hopefully you see this as a conservation of energy problem.
01:37
Our initial energy has to equal our final energy.
01:41
Our final energy is going to be our potential energy at 16 meters, plus our kinetic energy at five meters per second.
01:56
Our starting energy is going to be at whatever speed we throw it, which we're going to have to solve for, plus the mg, and i'll call it 8 -0, which is that two meters.
02:09
Now notice in this case, i'm going to go ahead and cross out the m's.
02:15
In this case, the velocity that it reaches at top, this would be v over here, the velocity reaches top is going to be 5 meters per second.
02:23
So that's the same in all three scenarios.
02:25
G is the same...