Two hoops, each of mass and radius '
' are joined with a hollow cylindrical tube of negligible mass, and radius '
' with the help of spokes as shown in the figure.
Assuming friction is sufficient to avoid slipping, find the acceleration of the block of mass ' ' which is connected with the cylindrical tube by a string of negligible mass, and going over an ideal pulley.

As the hoop is not slipping on the surface-

for point A:-
As the string is inextensible -
Applying conservation of energy when the block descend by ' ' and having velocity
Applying third equation of motion:-