Question

A bomb of mass 10 kg explodes into 2 pieces of mass 4 kg and 6 kg. The velocity of mass 4 kg is 1.5 m/s, the K.E. of mass 6 kg is ....... 

(A) 3.84 J 

(B) 9.6 J 

(C) 3.00 J 

(D) 2.5 J

Answer 1

Correct option: (C) 3.00 J

Explanation:

m₁ = 4kg

m₂ = 6kg

V₁ = 1.5 m/s

m₁v₁ + m₂v₂ = 0

(4) (1.5) + (6) (V₂) = 0

6V₂ = – 6

V₂ = – 1 m/s

KE of mass 6 kg = (1/2) m₂v₂² 

= (1/2) × 6 × (– 1)² 

= 3.00 J