Final answer:
The term 'RV' in the question likely refers to a variable related to the volume or pressure in a physics context. The pressure may be raised in a hot air balloon by heating the gas, in a tube by applying positive pressure to one side, or through an IV system by utilizing gravitational force.
Step-by-step explanation:
The question 'Where does the RV raise the pressure?' appears to be related to physics, specifically in the context of fluids and pressure dynamics. The term 'RV' could be referring to 'residential vehicle' in common discourse; however, in the context provided, it could be an abbreviation related to pressure or volume in a fluid dynamics scenario. If we consider 'RV' to mean 'relative volume,' the pressure could be raised in various scenarios such as when heating the gas inside a balloon, which causes the gas molecules to move faster and strike the walls with greater force, thus increasing pressure. Similarly, pressure could be altered by applying positive pressure to one side of a tube causing fluid to move to the opposite side. In a medical context, pressure could also be raised by having an IV bottle at a certain height above the entrance to a needle to ensure flow due to gravitational force assuming minimal pressure drop in the tubing.