Question

A cart is initially moving at 0.5m/s along a track. The cart comes to rest after traveling 1m. The experiment is repeated on the same track, but now the cart is initially moving at 1m/s. How far does the cart travel before coming to rest?

(A) 1 m 

(B) 2 m 

(C) 3 m 

(D) 4 m 

(E) 8 m

Answer 1

Correct option (B) 2m 

Stopping distance is found using v_f = 0 = v_i² + 2ad which gives d = v_i²/2a where stopping distance is proportional to initial speed squared.