Conservation of Momentum Question

[NoobeAtPhysics]

Homework Statement

We are learning momentum in physics class and I am having problems with this question.

i) An object at rest explodes into three pieces. Immediately after the explosion, two pieces have momenta given by F and A. Which vector describes the momentum of the third piece?

ii) An object at rest explodes into three pieces. Immediately after the explosion, two pieces have momenta given by B and C. Which vector describes the momentum of the third piece?

iii) An object at rest explodes into three pieces. Immediately after the explosion, two pieces have momenta given by D and E. Which vector describes the momentum of the third piece?

iv) An object moving with momentum E explodes into three pieces. Immediately after the explosion, two pieces have momenta given by V and D. Which vector describes the momentum of the third piece?

v) An object moving with momentum G explodes into three pieces. Immediately after the explosion, two pieces have momenta given by B and D. Which vector describes the momentum of the third piece?

Homework Equations

p=m*v

The Attempt at a Solution

i) C

ii) G

iii) A

iv) Hard one, R., I believe

v) C, I believe


/thank you/
noobe

 

[NascentOxygen]

i) An object at rest explodes into three pieces. Immediately after the explosion, two pieces have momenta given by F and A. Which vector describes the momentum of the third piece?

We need this and the other 3 parts to each be accompanied by a scaled diagram so we can check whether you are doing it correctly.

I agree with C here.

ii) An object at rest explodes into three pieces. Immediately after the explosion, two pieces have momenta given by B and C. Which vector describes the momentum of the third piece?

I don't agree with your answer.

Diagrams please.

 

[NoobeAtPhysics]

Hmm, do I have to measure each angle then use the formula?

Is there a way to look at it visually?

 

[NascentOxygen]

Graphically. You trace the lines, so you get length and angle correctly, and add vectors graphically on paper.