$\begin{array}{1 1}17.6J\\16.6J\\18.6J\\19.6J\end{array} $

Answer : 17.6J

From the free body diagram

$T-mg =ma$

$\Rightarrow T=m(a+g)$

$\quad\quad=2\times (2.2+9.8)$

$\quad\quad=24N$

$\therefore$ Work done by tension is (T and S are in the same direction)

$W_1=TS\cos 0^{\large\circ}$

$\Rightarrow 24\times 4\times 1=96J$

Since the gravitional force $mg$ and displacement S are in opposite directions,work done by gravity is

$W_2=mgS\cos 180^{\large\circ}$

$\Rightarrow -2\times 9.8\times 4 =-78.4J$

Net work done $W=W_1+W_2=96-78.4=17.6J$

Ask Question

Tag:MathPhyChemBioOther

Take Test

...