00:07
So we have the angle theta, we have the first mass here.
00:34
The weight is m1 times gravity and another mass is attached here, this m2 times gravity.
00:51
This mass has a, this weight has a component along the plane giving us m2g sine theta and a perpendicular component given by m2g cross theta.
01:07
The perpendicular component is balanced by reaction r and for equilibrium r equals m2g cost theta that is for equilibrium perpendicular to the plane.
01:28
Let's assume this body is the force here is greater and so friction tries to oppose the motion by acting downwards.
01:48
So the false trying to pull the body this way which is the weight of m1 g equals the forces trying to pull it the other way, which is mu r plus m2g sine theta.
02:05
So m1g equals mu r where r is m2g cross theta with substitute for r then plus m2g sin theta.
02:21
So g cancels out and our m1 which we are looking for is mu.
02:31
The coefficient of friction, which is 0 .47 times m2, which is 5 times cost theta.
02:46
Our angle theta is 30 .09 plus m2 again 5 times sine theta.
02:57
Theta...