Question

Same forces act on two bodies of different mass 2 kg and 5 kg initially at rest. The ratio of times required to acquire same final velocity is 

(A) 5:3 

(B) 25:4 

(C) 4:25 

(D) 2:5

Answer 1

Correct option: (D) 2 : 5

Explanation:

F × t = m(v₂ – v₁)

Ft₁ = m₁(v – v_o) = m₁v        as v_o = 0

Ft₂ = m₂(v – v_o) = m₂v        as v_o = 0

hence (Ft₁ / Ft₂) = (m₁ v / m₂ v)

(t₁ / t₂) = (m₁ / m₂) = (2 / 5)