Find the average force required to hold the gun in position

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
5 replies · 2K views
Joe_1234
Messages
24
Reaction score
0
A gun fires 6 bullets per second into a target. The mass of each bullet is 3g & the speed of 500 m/s. Find the average force required to hold the gun in position.
 
Mathematics news on Phys.org
Impulse equation ...

$F \cdot \Delta t = m \cdot \Delta v$
 
skeeter said:
Impulse equation ...

$F \cdot \Delta t = m \cdot \Delta v$
Tnx
 
You titled this "momentum" so it looks like you already knew the basic idea. The momentum of a single bullet is "mass times velocity" and you are given both of those. Of course, the momentum of 6 bullets is 6 times the momentum of a single bullet. Since this all happens in one second, divide by one second to get the force.

Be careful to use consistent units. You are given the mass in grams and the speed in m per second. Either convert mass to kg to get the force in Newtons or convert the speed to cm per second to get the force in dynes. I recommend the former.
 
Last edited by a moderator:
HallsofIvy said:
You titled this "momentum" so it looks like you already knew the basic idea. The momentum of a single bullet is "mass times velocity" and you are given both of those. Of course, the momentum of 6 bullets is 6 times the momentum of a single bullet. Since this all happens in one second, divide by one second to get the force.

calculating the impulse for one bullet over $\Delta t = \frac{1}{6} \text{ sec}$ yields the same result as six bullets in $\Delta t = 1 \text{ sec}$
 
Joe_1234 said:
Tnx
Serious question - is it harder to type “thanks” or “tnx “ on your phone? On mine the latter will auto correct to something else so it’s actually harder.