Answer:
r = 0.11 m
Explanation:
Let's suppose that the magnetic field is perpendicular to the vector speed. In that case, the centripetal force would be the same as the Lorentz force.
[tex] F=ma_{c}=qvB [/tex]
[tex] m\frac{v^{2}}{r}=qvB [/tex].
Solving this equation for r, we will have:
[tex] r=\frac{mv}{qB} [/tex]
Now, to find r we need to get the speed of the particle. Let's use the law of conservation of energy. The kinetic energy is equal to the electric potential energy:
[tex] U_{E}=K [/tex], but [tex] U_{E}=qV [/tex]
So we would have:
[tex] qV=1/2mv^{2} [/tex], then [tex] v=\sqrt{\frac{2qv}{m}} [/tex]
Finally [tex] r = m\frac{\sqrt{\frac{2qv}{m}}}{qB}= 0.11 m [/tex]
Have a nice day!