28. Magnetic Fields and Forces

Muons ( mass = 207 times the electron mass, same charge ― e ) are accelerated horizontally by 65 kV. They then pass through a uniform magnetic field B for a distance of 3.8 cm, which deflects them upward so they reach a detector 22 cm away, 11 cm above their original direction. Estimate the value of B.

(III) A 3.40-g bullet moves with a speed of 155 m/s perpendicular to the Earth’s magnetic field of 5.00 x 10⁻⁵ T . If the bullet possesses a net charge of 18.5 x 10⁻⁹ C , by what distance will it be deflected from its path due to the Earth’s magnetic field after it has traveled 1.25 km?

(II) An electron moves with velocity v (→ above v) = (6.0 î ― 7.0 ĵ) x 10⁴ m/s in a magnetic field B (→ above B) = (―0.80 î + 0.60 ĵ) T . Determine the magnitude and direction of the force on the electron.

(II) An electron experiences the greatest force as it travels 2.8 x 10⁶ m/s

in a magnetic field when it is moving northward. The force is vertically upward and of magnitude 7.4 x 10⁻ ¹³ N . What is the magnitude and direction of the magnetic field?

(I) Alpha particles (charge q = +2e, mass m = 6.6 x 10⁻²⁷ kg) move at 2.2 x 10⁶ m/s . What magnetic field strength would be required to bend them into a circular path of radius r = 0.14 m?

(I) An electron is projected vertically upward with a speed of 1.70 x 10⁶ m/s into a uniform magnetic field of 0.550 T that is directed horizontally away from the observer. Describe the electron’s path in this field.

(I) Determine the magnitude and direction of the force on an electron traveling 7.75 x 10⁵ m/s horizontally to the east in a vertically upward magnetic field of strength 0.65 T.