Aspring stores potential energy u0 when it is compressed a distance x0 from its uncompressed length. a] in terms of u0, how much energy does it store when it is compressed twice as much? uel/u0 =? b] in terms of u0, how much energy does it store when it is compressed half as much? uel/u0 = ? c] in terms of x0, how much must it be compressed from its uncompressed length to store twice as much energy? x/x0 = ? d] in terms of x0, how much must it be compressed from its uncompressed length to store half as much energy? x/x0 = ?

In the future, people will only enjoy one sport: electrodisc. in this sport, you gain points when you cause metallic discs hovering on a field to exchange charge. you are an electrodisc player playing the popular four disc variant. the disks have charges of qa = −8.0 µc, qb = −2.0 µc, qc = +5.0 µc, and qd = +12.0 µc. (1) you bring two disks together and then separate them. you measure the resulting charge of these two disks and find that it is +5.0 µc per disk. which two disks did you bring together? (a) a and b (b) a and c (c)a and d (d)b and c(e) b and d (f) c and d. (2) you bring three disks together and then separate them. you measure the resulting charge of these three disks and find that it is +3.0 µc per disk. which three disks did you bring together? a, b, and c (a) a, b, and d (c) a, c, and d (d) b, c, and d. (3) given the resulting charge of each disk measured in (b) is +3.0 µc, how many electrons would you need to add to a disk of this charge to electrically neutralize it? electrons