Question

The escape velocity for a planet is $v$. A particle starts from rest at large distance from the planet The planet only under gravitational attraction and passes through a smooth tunnel through its centre, speed at the centre of the planet will be:

Answer 1

Given, Escape velocity is $v$

So, $\frac{1}{2}{m}_0{v}^2=GmE\frac{m_0}{rE}$

$\Rightarrow v^2=2G\frac{mE}{rE}$