Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

The uniform 28.0 mT magnetic field in the figure points in the positive z direct

ID: 777018 • Letter: T

Question

The uniform 28.0 mT magnetic field in the figure points in the positive z direction. An electron enters the region of magnetic field with a speed of 5.50 × 106 m/s and at an angle of 30° above the xy-plane. (Figure 1) Part A Find the radius r of the electron's spiral trajectory Express your answer with the appropriate units alueUnits Submit Request Answer Part B Find the pitch p of the electron's spiral trajectory Express your answer with the appropriate units alue Units Submit Request Answer gure 1 of 1 Provide Feedback 30°

Explanation / Answer

(A) magnetic force is

FM=qv x B = qvBsin(/2-) = qvBcos

this force equals the centripetal force

FC=mv^2cos^2/r

then

mv^2cos^2/r=qvBcos

the radius of the spiral is

r=mvcos/(qB)

= (9.11*10-31)(5.5*106)cos30/(1.6*10-19 * 28*10-3)

= 9.69 x 10-4 m

(B)

the pitch is

p=vsinT

where

T=2r/(vcos)

then

p=2rtan

= 2*9.69 x 10-4 *tan30

= 3.51 x 10-3 m