Astudent standing on a stationary skateboard tosses a textbook with a mass of mb = 1.25 kg to a friend standing in front of him. the student and the skateboard have a combined mass of mc = 112 kg and the book leaves his hand at a velocity of vb = 3.61 m/s at an angle of 31° with respect to the horizontal.

randomized variables :

mt = 1.05 kg

mc = 104 kg

vb = 2.25 m/s

θ = 22 degrees

what is an expression for the magnitude of the velocity the student has after throwing the book?

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