Question

from a rifle of mass 4kg,a bullet if mass 50g is fired with an initial velocity of 35 m/s calculate the initial recoil velocity of the rifle​

Answer 1

Answer :

›»› The initial recoil velocity of rifle is 0.43 m/s.

Given :

• From a rifle of mass 4kg,a bullet if mass 50g is fired with an initial velocity of 35 m/s.

To Calculate :

• The initial recoil velocity of the rifle.

Calculation :

• Mass of rifle (m₁) = 4kg = 4000g.
• Mass of bullet (m₂) = 50 g.
• Initial velocity of bullet (u₂) = 35 m/s.
• Initial recoil velocity of rifle (u₁) = ?

Here in this question we have to find the initial recoil velocity of rifle. So, firstly we need to convert the SI unit of mass of rifle from kg to g, to convert the SI unit of mass of rifle multiply the mass value by 1000, after that we will find the initial recoil velocity of rifle on the basis of conditions given above.

→ Mass of rifle = 4 kg

→ Mass of rifle = 4 * 1000

→ Mass of rifle = 4000 kg.

According to the given question,

→ Momentum of rifle = Momentum of bullet.

→ m₁u₁ = m₂u₂

→ 4000 * u₁ = 50 * 35

→ 4000u₁ = 50 * 35

→ 4000u₁ = 1750

→ u₁ = 1750/4000

→ u₁ = 175/400

→ u₁ = 0.43

Hence, the initial recoil velocity of rifle is 0.43 m/s.