What is the acceleration of a proton moving with a speed of 7.5 m/s at right angles to a magnetic field of 1.7 t ?

The Lorentz force acting on the proton is:
(1)
where
q is the proton charge ()
v is its speed (7.5 m/s)
B is the magnetic field intensity (1.7 T)
is the angle between the direction of v and B, and since the proton is travelling at right angle to the magnetic field,  and , so we can ignore it.

The Lorentz force provides the centripetal force that keeps the proton in circular orbit. The centripetal force is
(2)
where
is the centripetal acceleration
m is the proton mass ()
v is the proton speed

We said that the Lorentz force provides the centripetal force of the motion, so we can equalize (1) and (2) to find the radius of the proton's orbit:



Therefore now we can calculate the centripetal acceleration of the proton, which is given by