An alpha particle travels at a velocity v of magnitude 620 m/s through a uniform
ID: 1438813 • Letter: A
Question
An alpha particle travels at a velocity v of magnitude 620 m/s through a uniform magnetic field B of magnitude 0.095 T. (An alpha particle has a charge of +3.2 10-19 C and a mass of 6.6 10-27 kg.) The angle between v and B is 46°.
(a) What is the magnitude of the force FB acting on the particle due to the field?
N
(b) What is the magnitude of the acceleration of the particle due to FB?
m/s2 (c) Does the speed of the particle increase, decrease, or remain equal to 620 m/s?
The speed of the particle decreases.The speed of the particle increases. The speed of the particle remains the same.
Explanation / Answer
a) FB =q ( v x B)
|FB| = |q||v| |B| sin@
|FB| = 3.2 x 10^-16 x 620 x 0.095 x sin46 = 1.36 x 10^-14 N
b) a = FB/m = (1.36 x 10^-14 ) / (6.6 x 10^-27) = 2.05 x 10^12 m/s^2
c)force will be always perpendicular to the velocity,.
(perpendicular force only can change direction not magnitude)
hence particle will perform cicrcular motion with constant speed.
so speed remains same.