# How do you firgure out distance from a shot fired from a sniper

spuding102
Given that you have the mass of the bullet and you can figure out the ΔHcombustion by bond breaking energies. I understand you can do W=F x D but and you can get work in jules but you cannot completely get force because F=MA and you only have M and not A.

How do you do it?

Gold Member
2021 Award
without knowing other factors it couldnt be worked out.
The mass of the bullet on its own is meaningless as it could have come from sized shells with different amounts of powder.

for example I used to own several different military style weapons, they were all 7.62 calibre bullets ( pretty common for that use) but the size of the shell and the amount of powder in each was quite different. They all had very different ranges for the same size calibre.

Dave

Staff Emeritus
Gold Member
Did you hear the shot?

Gold Member
2021 Award
Did you hear the shot?

if yes, then the bullet probably wasnt aimed at you ;)

D

anaximenes
It would be easy if you knew the mass of the gun and the kick of the gun in which case you set both forces equal
(h1 = h2)
Or use
Q= n(change in H)

Homework Helper
Gold Member
Time the distance between flash and bang?

anaximenes
Thats the speed of the bullet you need to divide the kick distance by the weight of the gun and then multiply that by the weight of the bullet

Mentor
@anaximenes: How is that related to the distance?

I would try to reconstruct the flight path and find the position of the sniper.
If that is not possible, try to get the muzzle velocity and the impact velocity, this might allow to calculate the distance.

Gold Member
@anaximenes: How is that related to the distance?

I would try to reconstruct the flight path and find the position of the sniper.
If that is not possible, try to get the muzzle velocity and the impact velocity, this might allow to calculate the distance.
There must be a similar problem in Astronomy - spotting changes and plotting the subsequent developments. A computer could monitor a panoramic image and recognise gun flashes using some stereoscopic bolt on (I know that doesn't go easily with a panoramic shot but that's a mere detail) and simply range-find the positions of gun flashes. This would be much more effective than wasting one or more human spotters and it would not nod off due to sheer boredom.

anaximenes
Because a gun shot is a explosion the kick of the gun will have an exual force to the gunshot, so if you mesure the kick distance, then multiply that by the whieght of the gun and divide that by the whieght of the bullet, you will know how far the bullet goes

anaximenes
equal , not exual

anaximenes
if you count the distance between flash and bang it willl only tell you how far you are from the gun