The relationship for the linear expansion of a solid, given by l-li + al s, is a valid approximation when aar is smal. laar is large, one must integrate the relationship d-a·87 to determine the final length. a) find a general expression for the firal length ly of a rod with an initial length її that unde its length vanes. (use the folong as necessary: l., and δη es a temperature change δ, assuming its coement ani esra pansiona is co stana, (b) the rod's initial length is 1.40 m, its temperature change is b0.0 c, and its a - 2.0010c)o typical value for a metal), what is the percent ermor caused by the approximation compared to the exact formula found in part (a)? (c) for the same length and temperature change as in part (b), what is the percent ermor caused by the approximation when 0,0200 c)-1 can unrealistically large value for comparison)?

Idon’t quite understand this problem

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

Athin nonconducting rod with a uniform distribution of positive charge q is bent into a circle of radius r. the central perpendicular axis through the ring is a z-axis, with the origin at the center of the ring. a) what is the magnitude of the electric field due to the rod at z = 0? n/c (b) what is the magnitude of the electric field due to the rod at z = infinity? n/c (c) in terms of r, at what positive value of z is that magnitude maximum? r (d) if r = 4.00 cm and q = 9.00 µc, what is the maximum magnitude? n/c