The Radius and Mass of the Earth Are 6 $\times$ 10⁶ M and 5

Multiple Choice

The radius and mass of the Earth are 6.4 $\times$ 10⁶ m and 5.98 $\times$ 10²⁴ kg. Assume that a meteor starts at infinity with zero velocity and is attracted to the Earth. Neglecting friction, the speed at which it will strike the Earth is

A) 36 km/h.
B) 11 km/h.
C) 100 km/h.
D) unknown; we cannot determine the answer without knowing the mass of the object.