Answer:

Step-by-step explanation:
 = radius of the loop
 = radius of the loop 
 = mass of the block
 = mass of the block
 = speed of the block at top of the loop at point A
 = speed of the block at top of the loop at point A
 = magnitude of acceleration of block at A
 = magnitude of acceleration of block at A
At point A, the block moves in a circle and hence experience centripetal force. Due to this centripetal force, the centripetal acceleration of the block can be given as 
