Question

A 10 gm Bullet is shot from a gun of mass 5 kg with a velocity of 400 metre per second what is the speed of required of the gun​

Answer 1

Explanation:

we know that total action and reaction are equal.

i.e 10/1000(400)=5(-v)

4=5(-v)

hence velocity gained by gun is

v=-4/5m/s

the minus sign indicates the opposite direction of velocity of the gun.

Answer 2

Given

• Mass of the Bullet = 0.02 kg
• Mass of gun = 7.5 kg
• Velocity of the bullet = 200 m/s

To Find

• Recoil Velocity

Solution

● m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

● As the everything initially would have a velocity of 0 m/s, i.e values of u₁ and u₂ are 0 m/s

✭ Recoil Velocity :

→ m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

• m₁ = 10 g = 10/1000 = 0.01 kg
• m₂ = 5 kg
• v₁ = 400 m/s
• v₂ = ?

→ 0 + 0 = (0.01 × 400) + (5 × v₂)

→ 0 = 4 + 5v₂

→ -4 = 5v₂

→ -4/5 = v₂

→ v₂ = 0.8 m/s

• Note that we have ignored the -ve symbol as we here are finding the recoil Velocity which is in the opposite direction of motion and hence can be neglected

∴ The recoil velocity of the gun is 0.8 m/s