In the pulley - block system shown in figure, strings are light. Pulleys are massless and smooth. System is released from rest. In `0.3` seconds

a) work done on 2 kg blocks by gravity is `6 J`
b) work done on 2 kg block by string is `-2J`
c) work done on 1 kg block by gravity is `-1.5 J`
d) work done on 1 kg block by string is 2 J

Options

A. only a, d are correct
B. only b , d are correct
C. only a,b,c are correct
D. All are correct

Answer

`(4)`

Explanation

`a = (2m_(1) - m_(2))/(2m_(1) +(m_(2))/2) g. T = (3m_(1)m_(2))/(4m_(1) + m_(2))g`
On 2kg block, `W_(1) = m_(10gx = m_(1)g(1/2 at^(2)),`
On 1 kg block, `W_(2) = m_(2)gx/2`