Q. A force of(5+3x)N acting on a body of mass 20 kg along the x-axis displaces it from x=2m to x=6m.The Work done by the force is
A) 20 J
B) 48 J
C) 68 J
D) 86 J
Explanation
(c) Force $F = (5 + 3x)N$
Work done $W = \int_{x_{1}}^{x_{2}}{F.dx = \int_{2}^{6}{(5 + 3x)dx}}$
$= \left\lbrack 5x + \frac{3x^{2}}{2} \right\rbrack_{2}^{6} = 68\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.