How may the speed of a bullet be measured with a simple apparatus?

Answer 1

By far the easiest way to measure the speed of a bullet is to set up a high speed movie camera to film the path of the bullet. In the background you have a long scale of distance showing millimetres.
You turn it on and fire the bullet.
The resultant images will be spaced apart by the distance travelled in the time between images exposed.
The distance travelled is then multiplied by the number of images the camera takes in one second.
And lo and behold the answer in mm per second is there before you.
I see by your name you are depressed.
If it is suicide by bullet you are planning, please dont, it tends to make one hell of a mess and somebody is going to have to clear it up.
It is less messy to commit suicide by holding your breath, there is then nothing to clear up.
Any way how can anybody be that depressed when you can ask questions for free?

Answer 2

Use the bullet to cut thin wires to start and stop a digital timer. Space the wires to match the precision of the timer - it may be hard to hit the second wire if it has to be yards from the first for a lower precision timer.
Mount two disks of paper on a shaft a couple of feet long (or more) and turn the shaft a known speed - either with a fixed RPM motor or by measuring rotation with a tachometer - Fire the bullet through the two disks. The holes will not line up because the disks turned while the bullet traveled between them. Using a plumb bob and a protractor, (or a fancy bench) put the first hole straight above the shaft and measure the offset angle of the second hole. The angular rotation with the RPM will give the time. Larger disks are easier to measure because of larger linear movement.
It is possible to move the gun uniformly- either rotating inside two cylinders of paper or shifting sideways along two panels of paper, but since this involves a bullet going off in some odd direction, not recommended.
A laser bore sight could mark where the bullet would hit if no gravity with a clamped gun. Measuring the drop from there and assuming a good figure for gravity would allow calculation of time and therefore speed.

Answer 3

Electronic speed gates and high-speed cameras are not needed. See the ref., about the ballistic pendulum.
A ballistic pendulum is a known mass m1 of an impact-absorbing material (a block of wood is appropriate) hanging by a lightweight rod attached to a hinge. You fire the bullet at the wood block and measure the height h of the resulting swing. (If it's a low-friction hinge you'll have sufficient time to make the measurement.) Then you need to know the mass m1 of the bullet. You can either dig it out of the wood or use mfr. data. From conservation of momentum,
m1v1 = (m1+m2)v2, and the answer desired is v1.
You can find the velocity v2 of the pendulum-plus-bullet at the bottom of the swing from v2 = sqrt(2gh).
So the whole formula is
v1 = sqrt(2gh)*(m1+m2)/m1
Admittedly this must be done with care. The gun should be in a bench vise and the pendulum backed up with a sheet of something tough like steel. And the usual precautions about sensible and legal gun use, hearing protection, etc. also apply. The neighbors may report you.
EDIT: The vertical shot method doesn't account for air resistance, which is a major factor.

Answer 4

just lie on the ground facing upwards with a rifle and a sports clock on each hands. Keeping the rifle vertically upwards, Press the trigger and the sports clock simultaneously. And stop the clock when bullet touches the ground. Note down the time t. divide this t by 2.
we know that potential energy = kinetic energy
then, gravitational potential mgh= mg(1/2gt^2) = 1/2mv^2 ;[ since, h= 1/2 gt^2 ]
Consequently,you can find the initial velocity of the bullet by the relation v = gt = 32t fit/s or 9.81t m/s

Answer 5

They use an apparatus on mythbusters all the time that is a sort of photogate. A photoeye recongnizes when the bullet enters the one side and another when it leaves. Knowing the time lapsed between entry and exit and the distance between the points the velocity can be calculated.

Answer 6

Well you could measure it two ways. You could shoot it and at the same time, start a timer and when it hits a target, stop the timer, and measure the distance between the gun and the target. velocity=distance/time Or you could shoot at a target on a pendulum and measure the angle that the pendulum receeds at to figure out the speed of the bullet in the pendulum target, and use the conservation of momentum to find the bullet's velocity before impact. The bullet would need to stick in the target though, like maybe a bullet proof box. momentum before=momentum after [(mass of bullet)(velocity of bullet)]+[(mass of target)(velocity of target)]=[(mass of bullet and target)(velocity of buttet and target)]

Answer 7

well in theory, if you shot a gun parrell to the ground and dropped a bullit from the same hight they will hit the ground at the same time. From there you will have 3 points 1) the hight of the gun when your shot it. 2) the spot on the floor where there bullit droppen 3) and the spot on the floor where the shot bullit landed. With these spots and the also takeing a stop watch reading of how long it took the bullit to drop u can use the formula "Distance = Rate X Time"
we know the distance and we know the time. we can plug them back in to get the rate or speed.