Physics

Problem

An object placed at a distance of twice the Earth's radius,

2R_E

, from the Earth is allowed to fall to the ground. The mass of the Earth is

M

. In the absence of any frictional forces, which of the following gives the speed at which the object will hit the Earth's surface? a.

\sqrt{\frac{GM}{2R_E}}

\sqrt{\frac{GM}{R_E}}

2\sqrt{\frac{2GM}{R_E}}

2\sqrt{\frac{GM}{R_E}}