Question

Please answer pic is attatched

Answer 1

For the bullet

Let the initial velocity be u₁

Let the final velocity be v₁

For the block

Let the initial velocity be u₂

Let the final velocity be v₂

Let the mass of the bullet be m₁

Let the mass of the block be m₂

Formula and concept :

By Law of Conservation of Energy :

Sum of initial momentum = sum of final momentum .

m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂

We know that v₁ = v₂ .

Let v₁ = v₂ = v

So : m₁ u₁ + m₂ u₂ = m₁ v + m₂ v

Conversions

m₁ = 10 g

    = 0.01 kg

m₂ = 900 g

     = 0.9 kg

u₁ = 400 m/s

u₂ = 0 m/s

Calculate the velocity

m₁ u₁ + m₂ u₂ = m₁ v + m₂ v

= > 0.01 × 400 + 0.9 × 0 = v ( 0.01 + 0.9 )

= > 4 + 0 = v × 0.91

= > 0.91 v = 4

= > v = 4 / 0.91

= > v = 4.395

ANSWER:

The velocity is 4.4 m/s