Homework Help: Artillery projectile motion problem

1. Feb 2, 2014

Zdub311

1. The problem statement, all variables and given/known data

An artillery shell is fired from the origin in the x direction(z is vertically upward) at an angle of 30degrees above the horizontal axis at a velocity of 3000 ft/s. after 2.5a the shell which weighs 100lb explodes into two pieces. The first piece to land weighs 30 lbs and lands at (900,400,0)ft at 4.5 s after the gun was fired. When and where does the other piece land? Neglect air resistance and assume
2. Relevant equations
Not sure on these but I have x_e=v cos theta(t) and z_e=v sin theta(t)_e -1/2gt_e^2 and t_e=o

3. The attempt at a solution

Really need some inspiration with this one guys. This is my first physics class btw!

Thank you for any attempted help.

2. Feb 2, 2014

jackarms

Looks like since the explosion is internal, you can conserve momentum in the x direction. Find out where and when the original shell explodes, and from the information about where the first piece lands, find out its momentum (in x direction) just before landing. That should let you solve for the momentum of the second piece at the explosion, and then you can use that to find its velocity and thus where and when it will land.