Question:

A shuttle moves between station A and B on earth along a vacuum tunnel which is a chord across the earth as shown. The shuttle moves on the bases of gravitational force only and the tunnel is friction

A shuttle moves between station A and B on earth along a vacuum tunnel which is a chord across the earth as shown. The shuttle moves on the bases of gravitational force only and the tunnel is frictionless. Find maximum speed attained by the shuttle. (g = 10 m/s²) (A)4 km/s (B)3 km/s (C)2 km/s (D)1 km/s