Question

A plate of mass $m$, length $b$ and breadth $a$ is initially lying on a horizontal floor with length parallel to the floor and breadth perpendicular to the floor. The work done to exect it on its breadth is

• A. $mg\Bigg[\frac{b}{2}\Bigg]$
• B. $mg\Bigg[a+\frac{b}{2}\Bigg]$
• C. $mg\Bigg[\frac{b-a}{2}\Bigg]$
• D. $mg\Bigg[\frac{b+a}{2}\Bigg]$

Answer 1

Answer: (C)

$mg\Bigg[\frac{b-a}{2}\Bigg]$

Answer 2

Initial height of centre of gravity$=\frac{a}{2}$ Fmal heig t o centre o gravity $=\frac{b}{2}$ Work done$=mg\Bigg[\frac{b}{2}-\frac{a}{2}\Bigg]$ $\, \, \, \, \, \, \, \, \, =mg\Bigg[\frac{b-a}{2}\Bigg]$