The problem -http://i244.photobucket.com/albums/gg16 ... j/prob.jpg
3) I thought answer was 4 because of mg = weight.
17) i thought 1 A/2 * 2L = > R
18) i thought 3) because need parallel circuit to make effective I smaller.
19) not sure how to do
32) not sure
33) I believed it was 2 but it might be 1 because of way + or - are defined
I thought it was C.
3) the answer is 2 because the question asks for the object MASS, not its weight. It's weight depends on gravity according to W = mg, but it's mass is constant, even if it is floating in space where gravity is zero.
17) R is proportional to L/A so if you double the length and half the area your new resistance is four times greater. (4).
Think about it. Resistance measures how tough it is for an electron to travel through a metal. If the metal is longer, it is more difficult to travel through, so INCREASING the wire's length should INCREASE the resistance. If the wire is thicker, the electron has more paths to take through the metal--or think of water flowing through a pipe. It is easier in a bigger pipe, right? So increasing the area DECREASES the resistance, and decreasing the area INCREASES the resistance. 2 divided by 1/2 is 4.
Sorry I'm getting bored. Someone else might help you with the others.