(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

For the situation described in Figure P31.32, the magnetic field changes with time according to the expression B = (8.00t^3 - 4.00t^2 + 0.800) T, and r2 = 2R = 5.00 cm.

Figure P31.32

(a) Calculate the magnitude and direction of the force exerted on an electron located at point P2 when t = 2.00 s.

2. Relevant equations

E = -0.5r(dB/dt)

F = qE + (qv X B)

3. The attempt at a solution

E = -0.5r(dB/dt)

F = qE + (qv X B)

Alright, the force equation should simplify to just F = qE because B is zero outside the circle.

When I plug in and get:

F = 0.5qr (24t^2-8t) and plug in for the values:

q = 1.602 x 10^(-19)

r = 0.05m

t = 2

I get: 3.204 x 10^(-19) which is wrong...

What am I doing wrong here?

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# Homework Help: Faraday's Law and electron force

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