00:01
In this problem, we have been given that there are two blocks, a and b, and these two blocks are connected by a light inextensible string.
00:10
And the coefficient of static friction between the surface and this block mb, that is given as 0 .4.
00:19
And this is also the coefficient of static friction between the rope and the support c.
00:25
So this is 0 .4 as well.
00:27
And the mass of block a, this is given as 12 kilograms and we are required to compute the smallest mass of this block b, for which this entire system is in equilibrium.
00:44
So here we simply use the idea that the friction force which will be acting on this block and b, it will be to the right side, and we see that this is the load, and this block.
00:58
B that's holding this load because this is maintained in equilibrium and we use this expression to get the friction force and the friction force on this block of mass mb that will be equal to the coefficient of friction multiplied with the normal force which is equal to the weight of this block b so let's consider its mass as m which is what we have to determine so we multiply the mass with the acceleration due to gravity to get the weight in accordance to this equation.
01:29
So we see that this is the friction force and let's take the tension force here as t2 and the tension force acting at this point is t1 let's say.
01:43
So that will be equal to the weight of this block a that will be 12 times the acceleration due to gravity.
01:50
So first we see that t1 it's equal to 12g and t2 this is equal to 0 .4 m g.
01:59
And now let's look at this support...