A mass M is lowered with the help of a string by a distance h at a constant acceleration g/2. The work done by the string will be :
Answer & explanation
Correct answer: option 1
Tension in the string :
\(T = M(g - a) = M(g - \frac{g}{2})\)
\(T = Mg\)
W = force x displacement = \(-\frac{Mgh}{2}\)
Negative sign is because tension is in the upward direction and displacement is in the downward direction.