Problem 1. (Millikan's Oil Drop Experiment) Millikan used tiny oil droplets and adjusted the electric field until the electric force balanced the weight of the droplet, and one of the droplets hovered in air. However, the drops are all different sizes and weights, and the amount of charge on each droplet also varies. So, the tuning of the electric field is different for droplets of different sizes, which carry different charges. Let us assume that the density of the oil Millikan used in his experiment is KE A. Calculate the mass (in ) of the hove0fig droplet if its radius is measured to be kg 65 um B. Calculate the electric field (in ") required to counter the weight of the above droplet if it carries a charge V/m 02 = 20? C. In the second trial, the hovering droplet has a mass of . It carries a charge of calculate the electric field (in ) required to counter the weight of this droplet. 10 kg 811 = ?0? V/m Problem 2. (Nuclear radiation) A. Pick all the correct statements about a-, B-, and y-rays a. o-rays are a stream of positively charged particles b. o-rays are a stream of negatively charged particles C. a-rays are a stream of uncharged particles B-rays are a stream of positively charged particles B-rays are a stream of negatively charged particles f . B-rays are a stream of uncharged particles v-rays are a stream of positively charged particles h. y-rays are a stream of negatively charged particles i. v-rays are a stream of uncharged particles