Final answer:
The motionless bowl of tomato soup is at rest as it is not changing position relative to the table. Convection currents may occur inside the soup, but the bowl itself is stationary. The internal motion of the soup such as viscosity or temperature changes do not affect the bowl's external motion.
Step-by-step explanation:
A steaming bowl of tomato soup sitting motionless on a table to cool is exhibiting no motion relative to the table; it is at rest. In physics, an object is considered to be at rest if it is not changing position relative to a reference point over time. While the soup itself may experience convection currents internally, as heated regions of the soup rise and cooler regions descend, the overall system (the bowl and the soup) is not exhibiting any external motion.
Considering other scenarios, if a can of tomato soup rolls down a ramp in a quality control process at a factory, thick soup might cause the can to roll slower due to the internal resistance to flow, known as viscosity. Similarly, a tomato in free fall is an example where the object is not at rest, as it accelerates towards Earth due to gravity at 9.8 m/s², unaffected by its internal structure, only its mass.
Lastly, when discussing temperature, placing a sealed can of soup over a heat source like a campfire can cause the can to explode due to the increase in kinetic energy of the molecules within, leading to greater pressure. However, in the case of the steaming bowl of tomato soup on the table, we are only examining the absence of motion, not temperature-related effects.