In the figure shown, the system is released from rest. Find the velocity of block A when block B has fallen a distance 'ℓ'. Assume all pulleys to be massless and frictionless.

Question

G1 Physics · Accepted Answer

Using the string constraint to relate the velocities of A and B and applying conservation of mechanical energy to the two moving masses gives v(A)²=gℓ/5. Therefore v(A)=√(gℓ/5), option A.