Momentum of an explosion problem. Desperately

[Alphonso]

Homework Statement

An object explodes into three equal masses. One mass moves east with a velocity of 15.0m/s. A second mass moves at a velocity of 10.0m/s at 40 degrees south of east. What is the velocity of the third mass?

I desperately need help, i forgot my notes at school over the weekend, and this is material from the beginning of the year and I am confused as to where to start. Any help/ suggestions with where to start would really be appreciated as this is diploma exam prep.

 

[alphysicist]

Hi Alphonso,

Homework Statement

An object explodes into three equal masses. One mass moves east with a velocity of 15.0m/s. A second mass moves at a velocity of 10.0m/s at 40 degrees south of east. What is the velocity of the third mass?

I desperately need help, i forgot my notes at school over the weekend, and this is material from the beginning of the year and I am confused as to where to start. Any help/ suggestions with where to start would really be appreciated as this is diploma exam prep.

You have the correct word "momentum" in the title. What is the momentum equation in the x-direction? in the y-direction?