Question

Identify each energy exchange as heat or work. Drag the appropriate items to their respective bins. melted wax

Answer 1

Heat

-The fireman extinguishes the fire with foam and cools the environment. (The foam is the system.)

-Steam condenses on skin, causing a burn. (The condensing steam is the system.)

Work

-Gases push up a cylinder in a car engine. (Gases are the system.)

Step-by-step explanation:

Heat is the transfer of thermal energy between systems, while work is the transfer of mechanical energy between two systems.

Pushing a cylinder up requires that a force be applied to the cylinder over a distance and is therefore work. When fireman extinguishes the fire with foam and cools the environment, energy is exchanged via heat, not via work. When steam condenses on skin, energy is exchanged via heat, not via work.

Answer 2

Heat

Step-by-step explanation:

Energy exchange occurs when two systems exchange energy between them, or a system exchange energy with its surroundings. This phenomenon can happen in two ways: heat or work.

The heat is the exchange of energy caused by the difference in temperature. So, when the systems lose heat, its temperature decreases, and when it gains heat, its temperature increases.

The work is the energy exchange caused by the difference in volume and pressure. When a gas expands, its volumes increase, and it does work to its surroundings. When it compresses, its volumes decrease and it suffers work from its surroundings.

So, when the wax melt, the temperature of it must have increased, and it has gained heat. The energy exchange as heat.