Question 40 unsaved if heat energy is transferred from direct contact between a warm object and a cold object, it has been transferred by question 40 options: 1) the sun 2) convection 3) conduction 4) radiation

3) conduction

Explanation:

Conduction is the process of heat transfer between solids, which require a material medium for its propagation. And in this case, heat would flow from the warm object to the cold one when in contact until they both reach a state of thermal equilibrum (neglecting heat loss to the surrounding).

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.

a is the correct answer