A second pendulum gives exact time at the foot of hill. It motions slowly for 10 seconds per day to get to the top of the hill. what is the height of the hill? Plz help. I have a exam tomorrow

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