Physics help please!!!!!?

Question

A 2g bullet is uniformly accelerated in a rifle barrel 1.2m long. If the bullet leaves the barrel with a speed of 300m/s, find the net force acting on the bullet in the barrel.

Answer 1

You need to find te acceleration since F = ma

Now from kinematics you know:

x = (v^2-v0^2)/(2a) where v = final speed., v0 = initial speed and x is the distance over which the acceleration a takes place.

So

a = (v^2-v0^2)/(2x)

Then F = ma = m(v^2-v0^2)/(2x) set v0 = 0

F =m(v^2)/(2x) = 0.002 kg*(300)^2 m^2/s^2/(2*1.2m)

F = 2x10^-3 * 9x10^4/(2.4) Nt

YOu can punch the numbers through your calculator.