Question

The acceleration due to gravity on a planet is $3/2$ times that on the earth. If length of a seconds pendulum on earth is $1$ m, length of seconds pendulum on the planet is

• A. $0.7m$
• B. $1m$
• C. $1.7m$
• D. $1.5m$

Answer 1

The correct option is D $1.5m$

$T=2\pi \sqrt{\frac{l}{g}}$
$T=2\pi \sqrt{\frac{l_1}{g_1}}$
$T=2\pi \sqrt{\frac{l_2}{g_2}}$
$e_1=l,g_2=g\frac{3}{2}$
$g_1=g$
$\frac{g}{1}=\frac{3g}{2e_2}$
$e_2=1.5m$