Question

please answer this question​

Answer 1

The final velocity of the combination will be 4 m/s

Explanation :

Initial velocity of 1st object , v₁ = 14 m/s

Initial mass of 1st object , m₁ = 2 kg

Initial velocity of 2nd object , v₂ = 0 m/s

Initial mass of 2nd object , m₂ = 5 kg

Final mass of the combination, M = 2 + 5 = 7 kg

From the law of conservation of momentum, the momentum before and after the collision should be constant.

=> m₁v₁ + m₂v₂ = MV

=> 2 x 14 + 5 x 0 = 7 x V

=> 7V = 28

=> V = 4 m/s

Hence the final velocity of the combination will be 4 m/s

Answer 2

Given mass of object 1 O₁ = 2 kg

mass of object 2 O₂ = 5 kg

Velocity of O₁ = 14 m/s

Velocity of O₂ = 0 m/s ( as the object is initially at rest )

Now total initial momentum of the object p₁ = m₁v₁ + m₂v₂ = 2×14 + 5×0

=28 kg m/s.

Now as per law of conservation of momentum we know

Total initial momentum P₁ = Total final momentum P₂

28 = (m₁+m₂)v

v = 28/(5+2) = 28/7

v = 4 m/s