A 4 gram piece of Zinc, with a specific heat of .388J/gC, is heated in a Bunsen Flame for 20 seconds. The zinc is then placed in a 45 ml water calorimeter. The calorimeter increased its temperature from 22.0 degrees Celsius to 23.2 degrees Celsius. What was the initial temperature of the metal after heating?

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.

The freezing and boiling point of a substance changes as the air pressure around it changes. for example, at a lower air pressure (higher altitude) it is easier for water molecules to escape from liquid into the air. in a high altitude city such as denver, colorado compared to a sea-level city such as houston, texas, water

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.