22. Let v

= v cos θ. The electron will proceed with a uniform speed v

in the direction of 

B while undergoing

uniform circular motion with frequency f in the direction perpendicular to B: f = eB/2πm

e

. The

distance d is then

d

=

v

T =

v

f

=

(v cos θ)2πm

e

eB

=

2π(1.5

× 10

7

m/s)(9.11

× 10

−31

kg)(cos 10

◦

)

(1.60

× 10

−19

C)(1.0

× 10

−3

T)

= 0.53 m .