Question

In $v-t$ graph shown in fig. the displacement of the body in $4$ seconds will be, if it starts from origin.

• A. $70\text{m}$
• B. $90\text{m}$
• C. $80\text{m}$
• D. $100\text{m}$

Answer 1

The correct option is B $90\text{m}$

Given $v-t$ curve as

So, displacement of the body is given by the area under the $v-t$ curve
$\Rightarrow D=(\frac{1}{2}\times (40-20)\times 2)+(20\times 2)+(20\times 1)+(\frac{1}{2}\times 1\times 20$ )
$\Rightarrow D=20+40+20+10=90\text{m}$