Physics Question on Forces?
by admin on Thursday, March 11th, 2010 | 2 Comments
Could someone please help me with this problem? I solved the first part but I don’t know what to do for the second part. Thanks A lot!
A 30-06 caliber hunting rifle fires a bullet of
mass 0.00486 kg with a velocity of 270 m/s to
the right. The rifle has a mass of 4.8 kg. What is the recoil speed of the rifle as the
bullet leaves the rifle?
I found the recoil speed: 0.273375 m/s
If the rifle is stopped by the hunter’s shoulder
in a distance of 3.35 cm, what is the mag-
nitude of the average force exerted on the
shoulder by the rifle?
Answer in units of N.
I think you should use the formula:
0.5* mv^2=Fx
energy conservation law: the initial moving energy=the accomplished work
i just think because I might have forgot the details after years.
Your answer of 0.273375 m/s is correct.
The energy of the rifle’s recoil is = (½) • m • V²
= (½) • (4.8) • (0.273375)²
= 0.17936 Joules
Work = F • d
0.17936 J = F • (0.0335 m)
F = 5.35 N