Sam blew up a balloon and rubbed it on his head. then he stuck the balloon on the wall. this was all the result of electrostatics or the transfer of charge. the appearance of negative charge on a balloon is the result of its gaining electrons. and these electrons must come from somewhere; in this case, from sam's hair. electrons are transferred in any charging process. in the case of charging by friction, they are transferred between the two objects being rubbed together. prior to the charging, both objects are electrically neutral and the situation obeys the law of conservation of charge. how does the law of conservation of charge explain sam and his balloon?
a) friction creates charge that collected on the balloon.
b) the balloon gained electrons; sam's hair gained protons.
c) if the balloon acquires charge, sam's hair loses charge.
d) the net charge before is zero; the net charge after is negative.

ben and jerry, arch rivals, decide to have a weight lifting contest during pe. ready, set, go! ben and jerry both lift a 250 kg barbell 10 times over their heads. they are approximately the same height and lift the barbell the same distance in the air. it takes ben 5 seconds to complete 10 lifts; it takes jerry 25 seconds to complete his 10 lifts.
which statement is most accurate regarding the weightlifting contest?
a) ben did more work than jerry.
b) ben has more power than jerry.
c) ben and jerry have the same power.
d) ben does more work and is more powerful than jerry.