Final answer:
The rise in temperature on a thermometer should be represented by a positive integer, consistent with the convention that increases in value are indicated by positive numbers in mathematics and the physical interpretation of temperature changes.
Step-by-step explanation:
If the temperature on this thermometer rises or ascends, you should illustrate this change with a positive integer. This is because, in mathematics, upward movement or an increase in value is conventionally represented by positive numbers. This aligns with the concept seen in Figure 2.7 where motion upward is considered positive.
Taking into account the behavior of temperature changes, if a substance gains thermal energy, this leads to an increase in temperature. As a result, the change in temperature (ΔT) is greater than zero, and the associated quantity of thermal energy (q) would also be represented as a positive value.
Additionally, when considering the direction of heat transfer, positive heat values indicate the absorption of heat by the system, while negative values would indicate the release of heat, as noted in the tips for successfully solving thermal efficiency problems.