# Mechanics Problem

1. Jun 14, 2007

### neelakash

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

A nucleus at rest undergoes spontaneous radioactive decayby emitting an electron of momentum 1.73 MeV/c and at right angle to to the direction of electron, a neutrino of momentum 1 MeV/c.Find the direction and momentum of the recoiling nucleus.
Here c is the velocity of light.

2. Relevant equations
3. The attempt at a solution

I CAN do this...but I am wondering if we are to employ the relativistic momentum concept...
Can anyone clarify?

2. Jun 14, 2007

### arunbg

If the momenta given in the question have been accurately determined, you don't even have to bother about whether you should use relativistic or classical equations. Both would turn up the same answer, since we make use of only momentum conservation. Now if the question were to do with something like velocity of recoil, for accuracy you should use relativistic calculations.

3. Jun 14, 2007

I see...
Thank you.