00:01
All right, we've got a proton that's going into a cyclotron, which will be with a magnetic field, which will cause the proton to circle.
00:12
We'll give it a circular motion.
00:16
We need to figure out that radius and show how we get that from the second law.
00:20
So the second law, newton's second law, is f equals m .a.
00:24
If the proton is moving in a circle, this is a centripetal force and a centripetal acceleration.
00:30
Which is found by v squared over r.
00:34
This centrippelof force is caused by the magnetic field, so by the magnetic force, which is the charge times the velocity, cross the magnetic field perpendicular to each other, so no theta there.
00:51
They would be equal to the same thing...