How did engineers solve this problem and make small-scale refrigerators and air conditioners possible? a. by bringing liquid water below its freezing point b. by capturing oxygen gas from the atmosphere c. by using a compression system to compress carbon dioxide into a liquid d. by developing new chemicals with new properties

A30 kg weight lies on top of a massless piston of area a = 0.01 m2 the exterior air is at a (constant) p =1 atm and t = 27 c. the interior gas is 0.4 moles of (ideal) n2 and it has initial temperature 27.00 degrees c. 1. what is the initial pressure in the interior? a. 29.4 kpa b. 130.7 kpa c. 101.3 kpa the next three questions concern what happens when an amount of heat q is slowly added to the interior, raising the piston by 1 mm and raising the interior temperature to 27.40 c

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.

Acamcorder has a power rating of 20 watts. if the output voltage from its battery is 9 volts, what current does it use?