Question

40 tom prepared a turkey at room temperature and heated the oven to 160 °c. he placed the turkey in the oven to cook. after the turkey was cooked for two hours, he inserted a thermometer into the turkey to check the temperature as shown. (a) state the temperature shown on the thermometer. 1 (b) state why the temperature of the turkey is not 160 °c even after two hours in the oven. 1

Explanation:

Part (a)

Step 1: Read the thermometer scale

The thermometer scale is in °C. The pointer is between 70 and 80? Wait, no, looking at the scale: the marks are 50, 60, 70, 80, 90, 100. Wait, the pointer is at 70? Wait, no, the scale: let's see, the numbers are 50, 60, 70, 80, 90, 100. Wait, the thermometer's pointer is at 70? Wait, no, maybe I misread. Wait, the scale: the major marks? Wait, the thermometer shows a scale where each major division? Wait, the diagram: the thermometer has a scale with 50, 60, 70, 80, 90, 100. The pointer is at 70? Wait, no, looking at the image (as described), the thermometer's reading: let's check the scale. The numbers are 50, 60, 70, 80, 90, 100. The pointer is at 70? Wait, no, maybe 70? Wait, the problem says "as shown" – the thermometer's scale: let's see, the marks between 60 and 80? Wait, no, the pointer is at 70? Wait, no, maybe 70 °C? Wait, the scale: 50, 60, 70, 80, 90, 100. So the temperature is 70 °C? Wait, no, maybe 70? Wait, let's confirm. The thermometer's scale: the numbers are 50, 60, 70, 80, 90, 100. The pointer is at 70. So the temperature is 70 °C.

The turkey is a solid (or has mass/heat capacity) and heat transfer (conduction/convection) takes time. Also, the oven's temperature is 160 °C, but the turkey, being a different object, will reach thermal equilibrium gradually, and may not reach the oven's temperature immediately (or at all, depending on heat transfer and heat capacity). Alternatively, the turkey has a specific heat capacity, so it takes time to absorb heat, and heat transfer from the oven to the turkey is not instantaneous; the turkey's temperature rises until it reaches thermal equilibrium, but maybe due to heat loss or its own heat capacity, it doesn't reach 160 °C in two hours. Another reason: the turkey is a conductor of heat, and heat transfer (conduction) from the oven (surroundings) to the turkey occurs until thermal equilibrium, but the turkey's mass and specific heat mean it takes time, and maybe two hours is not enough for it to reach 160 °C. Or, the oven's temperature is the ambient temperature, but the turkey, being a food item, has moisture, and evaporation (latent heat) could affect temperature, but more simply: The turkey and the oven are in thermal contact, but heat transfer (by conduction, convection) occurs, and the turkey's temperature increases until it reaches thermal equilibrium with the oven. However, due to the turkey's heat capacity (it needs to absorb a lot of heat to increase temperature) and the rate of heat transfer, after two hours, it hasn't reached 160 °C yet. Or, more simply: The turkey is not in thermal equilibrium with the oven yet; heat is transferred from the oven to the turkey, but the turkey's temperature is still rising (or has a lower temperature because it takes time to absorb heat, as it has mass and specific heat, so the temperature increase is given by \( Q = mc\Delta T \), so to reach 160 °C, it needs more heat or more time).

Answer:

70 °C

Part (b)