Question

At a distance of 10 R_e from earth's centre, where R_e is the earth radius the speed of an asteroid, headed directly towards earth, is found to be 12.0 km/s. What will be the asteroid's speed when it reaches earth's surface? (Neglect the effects of earth's atmosphere); R_e = 6400 km 

(a) 22.0 km/s 

(b) 16.0 km/s 

(c) 10.0 km/s 

(d) 8.0 km/s

Answer 1

Correct option (b) 16.0 km/s

Explanation:

Applying the energy conservation: