• # question_answer A particle falls towards the earth from infinity its velocity on reaching the earth would be- A)  Infinite     B)  ${{(gR)}^{1/2}}$        C)  ${{(2gR)}^{1/2}}$ D)  gR

Apply  C.O.M.E. T.E. at surface = T.E. at infinity $\frac{-GMm}{R}+\frac{1}{2}m.{{V}^{2}}=0$ $\Rightarrow \,V=\sqrt{\frac{2GM}{R}}=\sqrt{2gR}$