00:01
We got our glider on this frictionless air track, and the acceleration can be found by evaluating the forces acting on it.
00:10
So looking at the forces acting on this thing, because there's no friction and we're going to discount air resistance, we have two forces.
00:20
The weight force, which is straight down, and the normal force, which is perpendicular to the track.
00:25
So the part of the weight force that is parallel to the track, we can draw a little triangle there.
00:32
That parallel part is solely responsible for the movement of the cart.
00:39
The perpendicular part of the weight force will balance with the normal force.
00:44
So looking at the net force on this mass, this cart, it's going to be ma, and that will equal the parallel part of the weight force, m g times the sign of the angle of incline.
00:57
Now there's masses on both sides, so we can then solve this for the acceleration just by dividing by the mass.
01:04
And so we get the acceleration is equal to g, sine theta.
01:08
Now, in part b, we're going to release this from rest at the top of the ramp, and we can use kinematics to find the time...