The system of two masses 2 ~kg and 3 ~kg as shown in the figure is released from rest. The work done on 3 ~kg block by the force of gravity during first 2 seconds of its motion is (g=10 ~ms ⁻² )

Step-by-step solution

This is the example of Atwood machine, so acceleration is the system aligned a & = ( M-m M+m ) g a & = 1 5 10=2 ~m / s ^2 s & =u t+ 1 2 a t^2=0+ 1 2 2 (2^2 . s & =4 ~m aligned Now, s=4 ~m Work done on block of 3 ~kg by gravity aligned & W=M g s=3 10 4 & W=120 ~J aligned