Landon deliberately wrapped the wires around
the nails in different directions on each
electromagnet. he wants to test how this
difference affects the polarity of the
electromagnet. what object could landon use to
test this?
a. a paper clip
b. a bar magnet
c. a 3-volt battery
d. a piece of paper

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.