Question:
When a rubber-band is stretched by a distance $x$, it exerts restoring force of magnitude $\mathrm{F}=\mathrm{ax}+\mathrm{bx}^{2}$ where $\mathrm{a}$ and $\mathrm{b}$ are constants. The work done in stretching the unstretched rubber-band by $\mathrm{L}$ is:
$\mathrm{aL}^{2}+\mathrm{bL}^{3}$
$\frac{1}{2}\left(a L^{2}+b L^{3}\right)$
$\frac{\mathrm{aL}^{2}}{2}+\frac{\mathrm{bL}^{3}}{3}$
$\frac{1}{2}\left(\frac{\mathrm{aL}^{2}}{2}+\frac{\mathrm{bL}^{3}}{3}\right)$
Question of from chapter.
JEE Main Previous Year 2014
Correct Option: 3
Solution:
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