Calculating Recoil Velocity from Alpha Decay

[duke414]

The nucleus of ^214 {Po} decays radioactively by emitting an alpha particle (mass 6.65 * 10^-27 kg) with kinetic energy 1.23 * 10^{-12} J, as measured in the laboratory reference frame.

Assuming that the {Po} was initially at rest in this frame, find the magnitude of the recoil velocity of the nucleus that remains after the decay.



I'm not even sure where to begin. Any guidance in the right direction would be appreciated.

 

[ehild]

Think that the Po nucleus is a gun and the alpha particle is a bullet. The gun recoils when the bullet is fired. You can determine the recoil velocity, by applying a conservation law, what is it?

ehild

 

[duke414]

so i can use the kinetic energy to find velocity then use p = mv to calculate the recoil? can't believe i didnt think of it that way. thanks.

 

[ehild]

Always remember conservation of momentum when you hear "recoil"

ehild