The atmospheric pressure at the top and the bottom of a mountain are read to be 93.8 kpa and 100.5 kpa respectively. if the average density of air is 1.25 kg/m3, what is the height of the mountain? 683 m o 8200 m 547 m 5360 m

An inventor claims to have developed a reversed heat engine (ie. a heat pump) which is able to deliver 10 kj heat into the room at 20°c from outside ambient temperature of -10°c by consuming only 2 kj electricity in winter. this claim is a)-impossible b)-possible only if the heat pump is ideal c)-practically possible d)-unable to be assessed as it depends on the working fluid used in the heat pump.