Bullet of mass 10g is fired with speed 1000 m/s from gun of mass 2kg. Recoil speed of gun will be
Answers
Answer
Recoil velocity of the gun = - 5 m/s
Given
Mass of the bullet = 10 g = 0.01 kg
Velocity of the bullet = 1000 m/s
Mass of the gun = 2 kg
To Find
Recoil velocity of the gun = ? m/s
Key Points
This kind of question's can easily solved by the concept , Conservation of momentum
Solution
Mass of the gun , M = 2 kg
Mass of the bullet , m = 0.01 kg
Initial velocity of the gun , u = 0 m/s
Initial velocity of the bullet , u = 0 m/s
Final velocity of the bullet , V = 1000 m/s
Final velocity of the gun , v = ? m/s
This is the recoil velocity of the gun
Apply conservation of momentum ,
⇒ mu + Mu = mv + MV
⇒ (0.01)(0) + (2)(0) = (0.01)(1000) + (2)V
⇒ 0 + 0 = 10 + 2V
⇒ 2V = - 10
⇒ V = - 5 m/s
So , Recoil velocity of the gun = - 5 m/s
Note : Negative sign shows opposite direction of the gun