The Motion of a Charged Particle in Electric and Magnetic Field

Please review my solution to the problem and explain in detail what I may be doing wrong and what concepts I may not be applying correctly. I am not sure if I am apply the crossed fields concept correct in presuming that B is perpendicular.

The problem states:

An electron has an initial velocity of (12.0j + 15.0k) km/s and a constant acceleration of (2.00 x 1012 m/s2)i in a region in which uniform electric and magnetic fields are present. If B = (400μT)i, find the electric field E.

We know:
This is a crossed fields problem with the two fields perpendicular to each other.
B is perpendicular to v, out of the page.
Since B is perpendicular, it does no work on the electron but instead deflects it in a circular path.

q = 1.6 x 10-19 C
v = (12.0j + 15.0k) km/s = square root(12.02 + 15.02) = 19.21 km/s = 1.921 x 104 m/s
B = 400μT = 400 x 10-6 T = 400 x 10-6 N/Cm/s
Φ = 90º

E = qvBsinΦ
E = (1.6 x 10-19 C)(1.921 x 104 m/s)(400 x 10-6 N/Cm/s)(sin90º)
E = 1.229 x 10-18 N

Solution Summary

An electron moves with constant acceleration in presence of electric and magnetic field both. The electric field is calculated.

... The motion of charged particles in uniform ... The force on a charged particle (charge q) moving with velocity v in the presence of magnetic field B and ...

... a) i) Consider a charged particle of mass m and charge q which is moving in a uniform electric... Show that the equations of motion for the particle are,. ...

The motion of a charged particle in an electromagnetic field can be obtained from the Lorentz equation for the force on a particle in such a field. ...

... In our case the particles are electrons, hence ... The magnetic force on a charged particle q, moving with ... to the velocity, we get a centripetal (circular) motion. ...

... m/s When electric field is switched off, the centripetal force of circular motion is given by ... The solution finds the charge-to-mass ratio of the particle. ...

... Since the motion is circular, the force F which is a ... path (g) moves counterclockwise, therefore it is has positive charge and it ...Particle 1 2 3 4 5 6 7 8 9 10 ...

... 7 (which is for path d in fig.) which is having a negative charge and the direction of motion is clockwise shows that ... c. jdag Particle Mass Charge Speed 1 ...

... Thus, electric charges in motion generate magnetic... Electrons Photons Particles of matter Particles of light Have a rest mass Have no rest mass (All mass is ...