A 60-kg woman runs up a staircase 15 m high (vertically) in 20 s. Required:
a. How much power does she expend?
b. What is her horsepowerrating.

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

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?

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply