Question

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

• A. 70
• B. 270
• C. 35
• D. 135

Answer 1

The correct option is D 135

$w=\int Fdx$

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

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

$=[7x-x^2+x^3{]}_0^5$

$=[7\times 5-5^2+5^3]-[0-0+0]$

$=[35-25+125]-0$

$=135J$

In this question, answer is 135 J not 70J