Page 1 of 1

Magnetic Fields And Forces In An Alpha Particle.?

Posted: Thu Oct 12, 2017 7:12 am
An alpha particle (a Helium nucleus with 2 neutrons and 2 protons) has a charge of +2e and a mass four times larger than a proton, or 6.64E-27 kg. It is moving at a velocity of 3.6E6 m/s as shown in the figure when it enters a region (shaded in grey) of constant magnetic field. It moves in a semicircle of radius, R = 20 cm. Begin by drawing a free body diagram of the alpha particle showing the direction of the force just as it enters the grey area of constant field. (Ignore gravity)

http://session.masteringphysics.com/problemAsset/1000209843/7/ps-11-prep-4.jpg

a) What is the magnitude of the acceleration of the alpha particle just as it enters the grey area?

b) What is the direction of the acceleration of the alpha particle just as it enters the grey area?

c) What is the magnitude of the force on the alpha particle just as it enters the grey area?

d) What is the direction of the force on the alpha particle just as it enters the grey area?

e) What is the magnitude of the magnetic field inside the grey area?

f) What is the direction of the magnetic field inside the grey area?

g) If a single proton (charge = +e, m(proton) = 1.67E-27 kg ~ m(alpha)/4) enters the grey area with exactly the same velocity, what is the radius of its motion?

Thanks so much!