Solving Momentum Questions: 4 Homework Puzzles

[notinbutmatt]

I have 4 question for homework that i cannot figure out? Can u show me how to do them or at least start me off?
1. A cannon is rigidly attached to a carriage, which can move along horizontal rails, but is connected to a post by a large spring ,initally unstretched and with force constant k=2.00 x 10^4 N/m. The cannon fires from a 200 kg projectile at a velocity of 125 m/s directed 45 degrees.
a) If the mass of the cannon and its carriage is 5,000 kg, find the recoil speed of the cannon.
b) Find the maximum extension of the spring.
c) Find the maximum force the spring exerts on its carriage.
d) Consider the system consisting of the cannon, carriage and shell. Is the momentum conserved when firing? Why or Why not?
*I attaches a pic sorry that it is bad
http://img.photobucket.com/albums/v113/phatballar4/Jordan/physics.jpg

 

[OlderDan]

We ask that you show an attempt to solve problems before we start telling you what needs to be done. Here is a hint. There are two conservations principles at work here, and they can be applied sequentially rather than simultaneously.