An electron of kinetic energy 50 keV moves in a circular orbit perpendicular to a magnetic field of 0.405 T.

Find the radius of the orbit.

I tried using KE=mv^2/2 to find velocity. then using qBv=(mv^2)/r to solve for r. but my answer was wrong. I am pretty sure this is the method. I think my conversions may be wrong.

I have one submission left. would someone be able to run the numbers through quick?

Sure, I can help you with that. Let's break it down step by step.

1. Start with the equation for the kinetic energy of the electron in terms of its velocity:
KE = (1/2)mv^2

2. We need to find the velocity of the electron. To do that, we first need to convert the kinetic energy from keV (kilo-electron volts) to joules. Recall that 1 eV = 1.6 x 10^-19 J. Therefore, 50 keV = 50 x 1.6 x 10^-19 J.

3. Now, using the mass of an electron (9.1 x 10^-31 kg), solve the equation for velocity, v:
KE = (1/2)mv^2
v = sqrt((2KE) / m)

4. Plug in the values for the kinetic energy and the mass of the electron to find the velocity.

5. Next, we can use the equation for the centripetal force experienced by the electron in a magnetic field:
qBv = (mv^2) / r

6. Rearrange the equation to solve for the radius, r:
r = (mv) / (qB)

7. Plug in the values for the mass of the electron, the charge of the electron (q = -1.6 x 10^-19 C), the velocity, and the magnetic field strength to find the radius.

Make sure to use the correct values and units consistently throughout the calculations. If you recheck your conversions and follow these steps, you should be able to find the correct answer.