# Synch/Cyclotron equations help!

1. Feb 11, 2009

### ScotchDave

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

The formula for cyclotronic motion in SI units was shown to be p=qeBR. Show that in units in which R is in metres but p is in GeV/c p=0.3qBR

2. Relevant equations

$$qe^{-}=1.6 \times 10^{-19} C$$ I think!

$$L=\frac{\hbar \times c}{eV}= 1.9732705 \times 10^{-7} m$$ I think!

$$B = 1 eV^{2} = 1.44 \times 10^{-3} Teslas$$ I think!

3. The attempt at a solution

So, now I get even MORE confused and try substituting stuff in, but don't get anywhere!

$$p = \frac{10^{9}}{1.6 \times 10^{-19} \times 1.97x10^{-7} \times 1.44\times10^{-3}}} = 2.2 \times 10^{37}$$

or
$$p = \frac{10^{9} \times1.6 \times 10^{-19}}{ 1.97x10^{-7} \times 1.44\times10^{-3}}} = 0.56$$
This is clearly wrong, but I'm just getting COMPLETELY confused by all of this. Can anyone help me please?

Last edited: Feb 11, 2009