When the distance between two masses decreases to one-third of the original distance, the gravitational force between them a
increases to nine times as much.
b
decreases by one-half.
c
decreases by one-third.
d
increases to twice as much.
e
none of the above

The direction of the current in an alternating current circuit remains constant. is direct. changes repeatedly. changes randomly.

Which type of energy is transferred by convection currents?

When can a theory be modified if a new type of technology allows for new observations that raise new questions? a-immediately, while the questions about the theory are being asked b-after new hypotheses related to the theory are tested in experiments c-only after the new observations disprove all parts of the theory d-while scientists begin to think about how the theory could improve