What are the factors that keep a satellite in orbit

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

The total amount of energy contained in an object

Ascientist wants to test ways to reduce pollution in lake . what is the bestway of doing this