00:01
Okay, so this is the force diagram for the roller.
00:04
Let's take a look at a moment about point o.
00:06
Consider counterclockwise moment is positive, clockwise moment is negative.
00:10
And this will give us fa 1015 millimeter minus fc 10 150 millimeter is equal 0.
00:17
So i have fa is to fc, which means that the friction at point a is equal to the friction at point c.
00:25
So now let's apply force equilibrium for the roller.
00:27
So have net force along x direction is equal to p minus fc, minus n a, cosine 30 degree minus f a sine 30 degree is 0.
00:36
Na here is the normal force f .8, and p here is the force that was applied.
00:43
And along the wide direction, we have nc plus f a cosine 3 degree minus n a, sine 30 degree minus w, is good 0.
00:50
W here is the gravity of the roller.
00:55
So now let's take look at the force diagram for the tube.
01:00
So we'll consider the x direction of such model here, is along the surface and the wide direction is perpendicular to the surface.
01:10
So now let's take look at the moment about point d, which is the center of the circle here.
01:16
So consider counterclockwise moment is positive, clockwise moment is negative, and this will give us f8 times 150 millimeter minus fb times 150 millimeter is equal 0.
01:28
So we have f .a is equal fb, which means that the friction at point a is equal to friction at point b.
01:34
So now let's apply force equilibrium for this case.
01:37
So we have net force along x direction is equal to n .a minus fb minus wt sine 30 degree is 0.
01:44
So we have wt sine 30 degree is equal to na minus fb.
01:48
Wt here is the gravity for the tube.
01:52
And now on the y direction, we have nb minus fa minus wt cosine 3 degree is equal 3 degree is equal to nb minus fa.
02:01
So we assume that the slip occurs at point a.
02:04
Therefore, we have wt sin 30 degree is equal to n .a minus f a f .a., which is equal to na minus muana, since we assume that slip occurs at 0 .a.
02:15
So the friction at point a now is the static friction.
02:21
So if you do some arrangement here, eventually we have na is equal to wt 330 degree over 1 minus mua...