00:01
Okay, so the first case is the simplest case.
00:03
We have a pushing force that is directly horizontal, and we have a normal force, a friction force, and a weight force.
00:11
We know the mass and the coefficient of friction, and we know the pushing force is 224 newtons.
00:17
So in that first case with the horizontal pushing force, the normal force that it will feel will directly balance the weight force.
00:30
So the weight force being 200 newtons means that the normal force will also be 200 newtons.
00:37
And the friction force is going to be mu times that normal force.
00:42
So if the normal force is 200, we multiply that by 0 .2, and we get a friction force of 40 newtons.
00:51
That should be newtons there.
00:56
Let's make that clear clearly an n.
00:59
There we go.
01:01
And then for the net force, we have a pushing force to the right and a friction force to the left.
01:11
So the difference between those is 184 newtons.
01:14
And the acceleration that it will feel will be whatever that net force is divided by the mass.
01:20
So 1804 divided by 20, we get 9 .2 meters per second square.
01:25
So that's case one.
01:27
Case two, we are now pushing at an angle.
01:30
So our angle is going to look like this.
01:33
So we're going to have an x component and a y component.
01:37
And this angle, we can tell because the vector goes two blocks to the right and one block down.
01:45
So a tangent of that angle is 1 over 2...