What process is heat transfer through direct contact between solids?

What process is heat transfer through direct contact between solids?

• A. Conduction
• B. Radiation
• C. Convection
• D. Reflection

Answer: (A)

Conduction is heat transfer through direct contact between solids. When a hotter object touches a cooler one, the particles at the interface collide and exchange energy, so the hotter object cools down a bit and the cooler one warms up. In metals, free electrons move energy rapidly and help spread it quickly through the material. An everyday example is a metal spoon warming up from hot soup because the heat moves from the soup into the spoon through contact. Radiation transfers heat as infrared waves and can occur without contact, even in a vacuum. Convection involves the movement of a fluid, like air or water, carrying heat as it flows. Reflection is not a heat-transfer process.

Conduction is heat transfer through direct contact between solids. When a hotter object touches a cooler one, the particles at the interface collide and exchange energy, so the hotter object cools down a bit and the cooler one warms up. In metals, free electrons move energy rapidly and help spread it quickly through the material. An everyday example is a metal spoon warming up from hot soup because the heat moves from the soup into the spoon through contact.

Radiation transfers heat as infrared waves and can occur without contact, even in a vacuum. Convection involves the movement of a fluid, like air or water, carrying heat as it flows. Reflection is not a heat-transfer process.