From a rifle of mass 4 kg, a bullet
of mass 50 g is fired with an
initial velocity of 35 m s-
Calculate the initial recoil velocity
of the rifle.
Answers
Answer:
Given, the Bullet’s mass (m1) = 50 g
The rifle’s mass (m2) = 4kg = 4000g
Initial velocity of the fired bullet (v1) = 35 m/s
Let the recoil velocity be v2.
Since the rifle was initially at rest, the initial momentum of the rifle = 0
Total momentum of the rifle and bullet after firing = m1v1 + m2v2
As per the law of conservation of momentum, the total momentum of the rifle and the bullet after firing = 0 (same as initial momentum)
Therefore, m1v1 + m2v2 = 0
This implies that v2 = – m1v1 / m2
= – 50g x 35ms-1 / 4000g
= -0.4375 m/s
Therefore, the recoil velocity of the rifle is 0.4375 meters per second in the direction opposite to the trajectory of the bullet (backward direction)
Answer:
Mass of the rifle (m1) = 4 kg
Mass of the bullet (m2) = 50 g = 0.05 kg
Recoil velocity of the rifle = v1
A bullet is fired with an initial velocity (v2) = 35 m/s
Initially, the rifle is at rest.
Thus, its initial velocity (v) = 0
Total initial momentum of the rifle and bullet system
⇒ (m1+m2) × v = 0
The total momentum of the rifle and bullet system after firing
= m1v1 + m2v2
= (4 × v1 ) + (0.05 × 35)
= 4v1 + 1.75
According to the law of conservation of momentum
Total momentum after the firing = Total momentum before the firing
4v1 + 1.75 = 0
v1= -1.75 / 4
v1 = – 0.4375 m/s
The negative sign indicates that the rifle recoils backwards with a velocity of 0.4375 m/s.