Formative Practice 4.1 – Physics Form 4 Chapter 4

Question 1:
State what happens to two objects in thermal equilibrium. 

Answer:

When two objects are in thermal equilibrium they are said to have the same temperature.

During the process of reaching thermal equilibrium, heat, which is a form of energy, is transferred between the objects.

Net heat flow between the two objects is zero.

Question 2:
Is our body in thermal equilibrium with the environment? Explain your answer.

Answer:

Our body does not in thermal equilibrium with the environment because the process of homeostasis of human body will maintain the body temperature at 37⁰C irrespective of the surrounding temperature.

Question 3:
Aisyah uses an uncalibrated laboratory thermometer to determine the temperature of a liquid, θ°C. She finds that the length of the liquid column when the thermometer is put into the liquid is as shown in Figure 4.6. Calculate the temperature of the liquid, θ°C.



Answer:

𝐿₁₀₀ = 12 cm
L_θ = 4 cm
θ = ???

\begin{aligned} \theta & =\frac{L_\theta}{L_{100}} \times 100^{\circ} \mathrm{C} \\ \theta & =\frac{4}{12} \times 100^{\circ} \mathrm{C} \\ \theta & =33.33^{\circ} \mathrm{C}\end{aligned}