A proton travels at right angles through a magnetic field of 0.025 teslas. If the magnitude of the magnetic force on the proton is 1.8 × 10-14 newtons, what is the velocity of the proton? The value of q = 1.6 × 10-19 coulombs.
A. 1.8 × 105 meters/second
B. 1.8 × 106 meters/second
C. 2.5 × 106 meters/second
D. 3.8 × 106 meters/second
E. 4.5 × 106 meters/ second

Question

A proton travels at right angles through a magnetic field of 0.025 teslas. If the magnitude of the magnetic force on the proton is 1.8 × 10-14 newtons, what is the velocity of the proton? The value of q = 1.6 × 10-19 coulombs.
A. 1.8 × 105 meters/second
B. 1.8 × 106 meters/second
C. 2.5 × 106 meters/second
D. 3.8 × 106 meters/second
E. 4.5 × 106 meters/ second

souvik · Answer

use Lorentz force $$F _{mag}=q( v \times B)$$
since the proton travels perpendicular to the magnetic field $$F _{mag}=q v  B$$
calculate $v$