3. A proton moves in a particle accelerator of diameter 40 cm perpendicular to a Magnetic Field equal to 0.150 T. Find (i) the speed of the proton and (ii) the period of the motion, (iii) the work done on the proton by $vec{F}_B$, (iv) the kinetic energy of the proton when it emerges out of the cyclotron accelerated? Note: Do not write down the formula directly. Explain circular motion in terms of $vec{B}$, $vec{F}_B$, and $vec{v}$. [Hint: Rotational Kinetic Energy $K = frac{1}{2}Mr^2omega^2$.]
