Question

a girl stirs hot cocoa with a metal spoon. which process causes her hand to get warmer? radiation conduction convection insulation

Explanation:

• Radiation: Transfer of heat in the form of electromagnetic waves, no direct contact. Here, heat transfer is due to contact (spoon - hand), so not radiation.
• Conduction: Heat transfer through direct contact of particles. Metal spoon (a good conductor) is in contact with hot cocoa (high - temperature region) and then with the hand. Heat moves from high - temperature (cocoa - spoon part) to low - temperature (hand) region through particle - to - particle interaction in the spoon (conduction).
• Convection: Heat transfer in fluids (liquids and gases) due to density differences (bulk movement of fluid). Here, the main heat transfer to the hand is through the solid spoon, not a fluid - based bulk movement.
• Insulation: Materials that prevent or slow down heat transfer. Metal is a conductor, not an insulator.

Answer:

B. conduction