Question

If a person is pushing a box inside a moving train, the work done in the frame of earth will be
$\vec{s_{0}}=$displacement of the train relative to ground.
$\vec{s}=$displacement of the box w.r.t. train

• A. Zero
• B. $\vec{F}.\left(\vec{s}+\vec{s_{0}}\right)$
• C. $\vec{F}. \vec{s}$
• D. $\vec{F}. \vec{s_{0}}$

Answer 1

Answer: (B)

Displacement w.r.t. ground $=\vec{s}+\vec{s_{0}}$
Since train is moving with constant velocity net force acting on block is $=\vec{F}$
Therefore work done $=\vec{F}.\left(\vec{s}+\vec{s_{0}}\right)$