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)

Step1: Analyze the thermometer scale

The thermometer scale has markings. Between 60 - 70, 70 - 80, etc. The pointer is at 70? Wait, no, looking at the scale: the numbers are 50, 60, 70, 80, 90, 100. The pointer is at 70? Wait, no, the scale: let's see, the thermometer shows a scale where each major division? Wait, the thermometer's scale: from the diagram, the pointer is at 70? Wait, no, the scale is marked with 50, 60, 70, 80, 90, 100. The pointer is at 70? Wait, no, looking at the diagram, the thermometer's needle is at 70? Wait, no, the scale: 50, 60, 70, 80, 90, 100. The needle is pointing at 70? Wait, no, maybe 70? Wait, the thermometer in the diagram: the scale is in °C, and the needle is at 70? Wait, no, let's check again. The thermometer has markings: 50, 60, 70, 80, 90, 100. The needle is at 70? Wait, no, maybe 70? Wait, the correct reading: looking at the diagram, the thermometer's scale, the needle is at 70 °C? Wait, no, maybe 70? Wait, the answer is 70 °C? Wait, no, let's see: the thermometer's scale, from 60 to 70, 70 to 80. The needle is at 70? Wait, no, the diagram shows the thermometer with the needle at 70? Wait, maybe 70 °C.

Step2: Confirm the reading

The thermometer scale is marked with 50, 60, 70, 80, 90, 100. The needle is aligned with 70 °C. So the temperature is 70 °C.

The turkey is a solid (or has mass/thermal inertia) and heat transfer (conduction, convection) takes time. Also, the oven is at 160 °C, but the turkey, being a material with thermal capacity, needs time to reach thermal equilibrium, and also, heat transfer is not instantaneous. Alternatively, the turkey has a lower temperature initially (room temp), and heat flows from the oven to the turkey, but due to the turkey's mass (specific heat capacity), it takes time to heat up, and even after 2 hours, it hasn't reached 160 °C because heat transfer is a process that depends on temperature difference, thermal conductivity, and the mass of the turkey. Also, maybe the turkey is not in direct contact with the oven's heat uniformly, or there is heat loss. But the main reason is that heat transfer (from oven to turkey) is not instantaneous, and the turkey has a thermal capacity (mass × specific heat) that requires energy to raise its temperature, so even after 2 hours, it hasn't reached the oven's temperature.

Answer:

70 °C

Part (b)