How does magnetism help
Scientists Understand the
motion of Earths plates?

What happens to light waves from a star as the star moves away from earth?

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds

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?