A proton (π=1.67Γ10β27kg, π=1.6Γ10β19C) is accelerated from the rest through a potential difference of 600 V, then injected into a uniform magnetic field. Once in the magnetic field as shown in the figure and it completes half a revolution in 10 nsec.
a)What is the direction and the magnitude of the magnetic field?
b)What is the radius of the orbit?