Also, in that question that asked to show that the net force was zero. guyths! A lot of people in my class got confused! Yes, the forces on the coil cause it to rotate. But don't get confused between TORQUE and FORCE. The force on AB was 0.1 and the force on CD was 0.1 in the opposite direction...
The blue and red light:
Because the blue light had more energy per photon, then one watt of red light must be more intense than one watt of blue light. (Ie have more photons in it)
Force on AB:
This was a good question, though there was an angle given, you did not need it as the side AB was...
What media are you working with?
What's the conceptual idea behind it?
How much have you completed?
all that jazz
:)
In case you're curious, i'm doing an impressionist style series of acrylic paintings on the life of a woman forced into an arranged marriage.