Question

Given $t=2\pi \sqrt{\frac{l}{g}}$. If $t=1.1,g=32$ and $\pi =\sqrt{10}$, then the value of $l$ is

• A. $0.463$
• B. $0.296$
• C. $0.672$
• D. $0.968$

Answer 1

The correct option is D $0.968$

$t=2\sqrt{\frac{l}{g}}$ .....(1)

$t=1.1,g=32and\pi =\sqrt{10}$

squaring the first equation (1) we get ,

$t^2=4{\pi }^2\left(\frac{l}{g}\right)$

now substitute the values of $t,gand\pi$ given above to get $l$

$l=\frac{t^{2}g}{4{\pi }^2}=\frac{1.1\times 1.1\times 32}{4\times 10}=\frac{9.68}{10}=.968$