The gravitational force between two objects is 2000 N. The mass of each probe is reduced to one third of its original mass. How much the distance between two objects change to keep the gravitational force between them 2000 N?

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?