A student made the electromagnet shown and used it to pick up one sewing pin. Which change to the electromagnet would most likely allow it to pick up
two sewing pins?
A. Replace the nail with a thick roll of paper.
B. Double the length of the wires that connect it to the battery
C. Double the number of coils of wire around the nail.
D. Replace the nail with a large steel bolt.

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge, at the position of the second charge, change if the second charge is doubled? a. the field does not change b. the field strength decreases by half. c. the field strength doubles d. the field strength quadruples

Assume that two of the electrons at the negative terminal have attached themselves to a nearby neutral atom. there is now a negative ion with a charge -2e at this terminal. what are the electric potential and electric potential energy of the negative ion relative to the electron? the electric potential and the electric potential energy are both twice as much. the electric potential is twice as much and the electric potential energy is the same. the electric potential is the same and the electric potential energy is twice as much. the electric potential and the electric potential energy are both the same. the electric potential is the same and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron. the electric potential is twice as much and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron.