A washing machine uses 1.8 × 105 watts of power. If it is in use for 2 hours per day (on average), how many kilowatt hours will it use in 30 days? A. 1.1 × 104 kilowatt hours B. 36 kilowatt hours C. 18 kilowatt hours D. 540 kilowatt hours E. 1.1 × 106 kilowatt hours

What is the earliest point in the universe that we can observe? why can’t we see back further than this?

Air is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. air enters the heat exchanger at 95 kpa and 20°c at a rate of 0.6 m^3/s. the combustion gases (cp = 1.10 kj/kg°c) enter at 160°c at a rate of 0.95 kg/s and leave at 95°c. determine the rate of heat transfer to the air and its outlet temperature.

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?