Recoil Speed?

Question

A rifle has a mass of 5.46 kg and it fires a bullet of mass 10.3 g at a muzzle speed of 816 m/s. What is the recoil speed of the rifle as the bullet leaves the gun barrel?

Answer 1

conservation of momentum.

momentum before = momentum after

Before: the riffle + the bullet
after: the riffle alone, the bullet alone

(m1+m2)v = m1v + m2v

initially, both the the riffle and bullet are not moving so the initial momentum is 0

0 = m1v + m2v
0 = (5.46)v + (.0103) (816)

now just solve for v. You'll get a negative answer, it just means the recoil velocity of the riffle is opposite of the velocity of the bullet

hope this helps

Answer 2

Conservation of momentum...

M = 5.46 kg
m = .0103 kg

The thing to note here is that right before the pull of the trigger, the rifle, bullet system was NOT moving, hence the initial momentum is 0. Thus the final momentum is zero!

Pi = Pf

0 = MV - mv

MV = mv

V = mv/M = .0103 * 816 / 5.46 = 1.53 m/s in the opposite direction as the bullet.

Answer 3

First state your givens:
M1 = 5.46kg
M2 = 10.3 g or .0103 kg
Vo1 = Vo2 = 0.0 m/s
Vf2 = 816 m/s
Vf1= ?

Now you know that all momentum is going to be conserved so:

Po = Pf
M1Vo1 + M2Vo2 = M1Vf1 + M2Vf2
0 = M1Vf1 + M2Vf2
Vf1 = (-M2Vf2)/ M1
Vf1 = (-.0103 * 816) / 5.46
Vf1 = - 1.54 m/s

It is important to note that the negative means opposite direction than the bullet.

Hope this helps.

Answer 4

Physics is the way you calculate real international activities, no longer unavoidably the way it truly works. besides, a contact i'd grant is that a similar volume of stress or power that propels the bullet from the gun also propels the heavy rifle the option route. So the base line is to apply easily one of your undemanding physics equations, and the speed and weight of the bullet, to discover the stress. Then use this stress and the burden of the rifle to discover the speed of the rifle. desire this helps. EDIT got here across it, you want the equation for impulse. impulse=mass x speed, on your problem impulse=.00484kg x 516m/s you get impulse = 2.479 kg-m/s now use this impusle and the a lot heavier mass of the rifle to discover the speed of the rifle.