The symbiotic relationship of the blue-green algae

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?

What is the magnitude of the gravitational force acting on the earth due to the sun?

Given the data calculated in parts a, b, c, and d, determine the initial rate for a reaction that starts with 0.85 m of reagent a and 0.70 m of reagents b and c?