What is matterwhat is the definition of matter

What is the internal energy of 4.00 mol of diatomic nitrogen gas n2 at 455k

Amanometer is used to measure the air pressure in a tank. the fluid used has a specific gravity of 1.25, and the differential height between the two arms of the manometer is 34 in. if the local atmospheric pressure is 12.7 psia, determine the absolute pressure in the tank for the cases of the

Can anybody me with this? ? (picture included.)