Came across this one in my freshman physics book:
A particle of mass 1m is traveling along the x-axis at velocity V1. It collides elastically with a second particle of mass 3m traveling at velocity V2. The first particle (1m) moves off at 0.92m/s at 48º to the x-axic. The second particle (3m)...
Let me try to better explain my thinking.
Break the wire into infinitesmially short segments length d_theta, so that each segment approximates a straight wire with a radially symmetric magnetic field.
Calculate the magnetic field dB, as resulting only from segment d_theta, using Ampere's...
Why can't I use Ampere's law to compute the magnetic field at the center (P) of a semi-circular wire?
If I calculate B at P due to d_theta, and then, using superposition, integrate from 0 to pi,
the result is B=uI/2R.
Biot-Savarte law gives the correct answer of B=uI/4R.