The soil temperature in the upper layers of the earth varies with the variations in the atmospheric conditions. before a cold front moves in, the earth at a location is initially at a uniform temperature of 10°c. then the area is subjected to a temperature of -10°c and high winds that resulted in a convection heat transfer coefficient of 40 on the earth’s surface for a period of 10 h. taking the properties of the soil at that location to be k = 0.9 and alpha = 1.6 x 10^5, determine the soil temperature at distances 0, 10, 20, and 50 cm from the earth’s surface at the end of this 10 h period.

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