Physics - Circular Motion Question with Solution | TestHub

Given, the mass of block$\left(m\right)=1\mathrm{ }\mathrm{k}\mathrm{g}$

The velocity of the block at time$t=2\text{s}$is$-3\mathrm{ }\mathrm{m} {\mathrm{s}}^{-1}$

Impulse during$t=2\mathrm{ s}$to$t=4\mathrm{ s}$.



From the graph,

$I=\mathrm{A}\mathrm{r}\mathrm{e}\mathrm{a}\mathrm{ }\mathrm{o}\mathrm{f} \mathrm{\Delta ABC}+\mathrm{A}\mathrm{r}\mathrm{e}\mathrm{a}\mathrm{ }\mathrm{o}\mathrm{f} \mathrm{\Delta CDE}$

$=\frac{1}{2}\left(3-2\right)\times 5+\frac{1}{2}\mathrm{(}4-3\mathrm{)}\mathrm{(}-5\mathrm{)}$

$=\frac{5}{2}-\frac{5}{2}=0$

We know that,

Impulse = Change in momentum

$0=m{v}_f-m{v}_i$

$\Rightarrow m{v}_f-m{v}_i=0$

$\Rightarrow m{v}_f=m{v}_i$

$v_f=v_i=-3\mathrm{ }\mathrm{m} {\mathrm{s}}^{-1}$or$|3\mathrm{ }\mathrm{m} {\mathrm{s}}^{-1}|$