acceleration of block A varies with time as shown in the figure the value of coefficient of kinetic friction between block A and B is
Answers
Pre-reading: Force is applied on block B. The moment when the block A starts sliding is the moment when the applied force F is greater than the frictional force between the two blocks. The moment when the applied force F is maximum such that there is no relative motion between the two blocks (I mean that the block A has not yet started sliding) the frictional force acting is limiting friction and when F is slightly larger than the block A starts sliding and the frictional force acting is Kinetic friction. Answer: When block A starts sliding the acceleration of A is 4.9m/s² So, there would be some value of coefficient of kinetic friction which is responsible for the motion of A with this acceleration. Simple applying Newton's 2nd law, ma(A) = μmg a(A) = μg 4.9 = μ•9.8 μ = 0.5 Please note that μ here is actually μk and a(A) is the acceleration of block A.
Answer:
The moment block A starts sliding is the moment the applied Force is greater than F
For A block:
ma= umg
4.9=u * (9.8)
u = 0.5