# Collisions problem

1. Feb 13, 2008

### bondgirl007

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

a 600 kg canon, initially at rest, exploded upon firing and broke in to three fragments. One fragment of mass of 200 kg travelled east at 40m/s and a second fragment of mass 300 kg travelled due south at 20 m/s. What was the velocity of the third fragment?

2. Relevant equations

sum of P = sum of P'
0= P1 + P2 + P3

3. The attempt at a solution

I'm not sure whether I'm supposed to use trig or something to find the missing velocity.
Any help would be GREATLY appreciated.

2. Feb 13, 2008

### PhanthomJay

Momentum is a vector quantity, and as such, the sum of the momenta must obey the laws of vector additions. Are you familiar with resultants and vector sums?

3. Feb 13, 2008

### bondgirl007

This is what I have so far. Am I on the right track?
Will the resultant be the hypotenuse?

http://img408.imageshack.us/my.php?image=physicsay5.jpg

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4. Feb 13, 2008

### bondgirl007

I did Pythragoras to find the missing vector.

(8000)^2 + (6000)^2 = c^2
c=100 m/s

tan$$\theta$$ = 6000/8000
$$\theta$$ = 37

I got 100 m/s for my velocity and 37 degrees N of W. Is this right?

5. Feb 14, 2008

### physixguru

You know anythin about momentum conservation????

6. Feb 14, 2008

### PhanthomJay

Yes, that is correct, but your diagram and equation are not consistent with this answer. Looks like you combined a step when solving for 'c' , and the direction of the diagonal is wrong.