Acurrent i travels counterclockwise through a closed copper wire loop which has the shape of a rectangle with sides 'a' and 'b'. what is the magnitude of the magnetic field at the center, c, of the rectangle? express your answer in terms of a, b, i and mu _0. (enter mu_0

Explanation:

The input force is the push or pull that you do on a machine.

In the first picture, the input force is the down arrow on the end of the crowbar.

In the second picture, the input force is the down arrow on the rope.

In the third picture, the input force is the up arrow on the handles of the wheelbarrow.