- #1
myxomatosii
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Homework Statement
In a ballistics test, a 25 g bullet traveling horizontally at 1200 m/s goes through a 35 cm thick 350 kg stationary target and emerges with a speed of 850 m/s. The target is free to slide on a smooth horizontal surface.
(a) How long is the bullet in the target?
(b)What average force does it exert on the target?
(c) What is the target's speed just after the bullet emerges?
Homework Equations
It would be nice to have some more equations, my professor gave the class four pages of equations scribbled in his horrible hand-writing, to help us... I guess. Instead of giving us the basic equations that we can use to plug-in to create our own equations he already solved them all out into the forms he understands, which means we have to un-solve them to try to make sense of them, so really I have no idea what other equations to put here since he has no clear division between which equations go with which section of the book.
momentum of system before = momentum of system after ||| Pi=Pf
The Attempt at a Solution
I already solved part C using the equation provided.
Part A I attempted something that I knew wouldn't work but gave it a try anyway and I know I need part A to solve B so I haven't gotten around to trying to solve B yet.
I seem not to be able to resist applying simple mechanics to complex problems just to see if I can knock it out of the way. Anyway I did this to solve for B, it was obviously going to be wrong but I submitted it anyway.
B: I tried to say that the
DT=0.35m
Vavg/DT=? Then that gave me seconds so I took s-1. Yea, it obviously was just bs, but that is how lost I am.