Q. A spring of spring constant $5 \times 10^{3}\ N/m$ is stretched initially by $5\ cm$ from the unstretched position. Then the work required to stretch it further by another $5cm$ is
A) $6.25\ N$-$m$
B) $12.50\ N$-$m$
C) $18.75\ N$-$m$
D) $25.00\ N$-$m$
Explanation
(c) $W = \frac{1}{2}k\left( x_{2}^{2} - x_{1}^{2} \right) = \frac{1}{2} \times 5 \times 10^{3}\left( 10^{2} - 5^{2} \right) \times 10^{- 4} = 18.75\ J$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.