Question

2 queations:
1) a proton enters a magnetic feild at a right angle to the field. an alpja particle enters the same field at the same angle but with twice the speed. once in the magnetic field both particles move in a circular path. the raito of radius of the alpha particles path to the radius of the protons path is?
[4:1]

2) a proton and an alpha particle have an identical circular orbits in a magnetic field. the proton has a speed of 4.4 m/s. the speed of the aplha particle is?
[2.2^5 m/s]

thank you

Answer 1

1) r = m*v/(q*B)
r(a)= m(a)*2v/(q(a)*B).....(1)
r(p)= m(p)*v/(q(p)*B).....(2)

r(a)/r(p)= m(a)*2v*q(p)/[m(p)*v*q(a)]
= 4m(p)*2*q(p)/[m(p)*2q(p)]
= 4*2/2 = 4

2) Ma*Va/[Qa*B] = Mp*Vp/[Qp*B]
So, Va = 4.4*2/4 = 2.2m/s