Question

A particle moves along $x-$axis from $x=0$ to $x=5$ meter under the influence of a force $F=7-2x+3x^2$. The work done in the process is:

• A. $70$
• B. $135$
• C. $270$
• D. $35$

Answer 1

The correct option is B $135$

Given,

$F=3x^2-2x+7$

Work done $=\int F\cdot ds$

$={\int }_0^5({3x}^2-2x+7)dx$

$={\left[\frac{{3x}^3}{3}-\frac{{2x}^2}{2}+7x\right]}_0^5$

$=(5{)}^3-(5{)}^2+7\times 5-0$

$=125-25+35$

$=135J$