Question

It's urgent.

A 30 g bullet leaves a rifle with a velocity of 300 m/s and the rifle recoils with a velocity of 60 cm/s.

Find the mass of the rifle​

Answer 1

Answer :-

Mass of rifle = 15 kg

Step-by-step explanation :-

Given:

• Mass of bullet = m₁ = 30 g = 0.03 kg
• Velocity of bullet = v₁ = 300 m/s
• Velocity of rifle = v₂ = 60 cm/s = 0.6 m/s

To find:

Mass of rifle = m₂ = ?

Solution:

By law of conservation of momentum,

Momentum of bullet = Momentum of rifle

→ m₁v₁ = m₂v₂

→ 0.03 × 300 = m₂ × 0.6

→ 0.03 × 3 × 100 = m₂ × 0.6

→ 9 = m₂ × 0.6

→ m₂ = 9 ÷ 0.6

→ m₂ = 15 kg

∴ Mass of rifle = 15 kg

Answer 2

Explanation:

$\mathfrak \purple{given \: that}$

Mass of bullet = m₁ = 30 g = 0.03 kg

Velocity of bullet = v₁ = 300 m/s

Velocity of rifle = v₂ = 60 cm/s = 0.6 m/s

To find:

Mass of rifle = m₂ = ?

Solution:

By law of conservation of momentum,

Momentum of bullet = Momentum of rifle

→ m₁v₁ = m₂v₂

→ 0.03 × 300 = m₂ × 0.6

→ 0.03 × 3 × 100 = m₂ × 0.6

→ 9 = m₂ × 0.6

→ m₂ = 9 ÷ 0.6

→ m₂ = 15 kg

∴ Mass of rifle = 15 kg