AS we can see the maximum value of acceleration with which the body can move together is 5 m/s 2this acceleration corresponds to the limiting frictional value acting between the two masses but once after a small jerk the block A is moved at the limiting case it starts to move owing to the fact that its maximum value of kinetic friction is less than the limiting frictionnow when block moves it has acceleration of 4.9 m/s2, so let μk be the kinetic friction coeffecient so when the body moves the value of frictional force acting on A block i s μkmgthus acceleration due to it is a = μkmg/m = μkggiven μkg = 4.9or μk = 4.9/9.8 = 0.5
