One of your authors was once involved in a research study where a newly developed pain drug was being tested. All participants completed a series of tasks intended to represent various types of somatic pain (e. g., a sharp, fast pain, a dull ache, etc.), and were asked to report how much pain they experienced during each task. The pain series was completed both during an initial visit to the lab, and during a second visit about a week later. Prior to completing the tasks during the second visit, participants received either the new pain drug or a placebo. What primary ethical guidelines apply to this experiment? Would any other guidelines apply if the study participants were made up of a group of patients actively receiving treatment for a pain disorder?

In a thunderstorm, charge builds up on the water droplets or ice crystals in a cloud. thus, the charge can be considered to be distributed uniformly throughout the cloud. for the purposes of this problem, take the cloud to be a sphere of diameter 1.00 kilometer. the point of this problem is to estimate the maximum amount of charge that this cloud can contain, assuming that the charge builds up until the electric field at the surface of the cloud reaches the value at which the surrounding air breaks down. this breakdown means that the air becomes highly ionized, enabling it to conduct the charge from the cloud to the ground or another nearby cloud. the ionized air will then emit light due to the recombination of the electrons and atoms to form excited molecules that radiate light. in addition, the large current will heat up the air, resulting in its rapid expansion. these two phenomena account for the appearance of lightning and the sound of thunder. take the breakdown electric field of air to be eb=3.00ă—106n/c. part a estimate the total charge q on the cloud when the breakdown of the surrounding air is reached. express your answer numerically, to three significant figures, using ďµ0=8.85ă—10â’12c2/(nâ‹…m2) .