At what distance above the surface of the earth is the acceleration due to the earth's gravity 0.855 m/s2 if the acceleration due to gravity at the surface has magnitude 9.80m/s2?

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?