Grabbing a warm coffee mug to warm your hands is primarily an example of conduction. Conduction is the transfer of heat through direct contact between materials. When you hold the warm mug, heat transfers from the mug to your hands through direct contact.
In terms of the other two processes:
- Convection involves the transfer of heat through the movement of fluids (liquids or gases), which is not applicable here since you are not moving warmer air or liquid to warm your hands.
- Radiation is the transfer of heat in the form of infrared radiation and does not specifically involve direct contact, although some heat can be radiated from the mug to your hands.
So, the warming of your hands from the mug is best described as conduction.