Question

A particle moves along the x-axis from $x=0$ to $x=5 \, m$ under the influence of a force given by $F= \, 7 \, - \, 2x \, + \, 3x^{2}$ . The work done in the process is-

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

Answer 1

Answer: (D)

$W=\displaystyle \int F.dx=\displaystyle \int _{0}^{5} \left(\right. 7 - 2 x + 3 x^{2} \left.\right) \, dx$
$=\left[7 x - \frac{2 x^{2}}{2} + \frac{3 x^{3}}{3}\right]_{0}^{5}$
$=35-25+125=135 \, J$