Transfer of thermal energy

A series of readings is to be taken so that a cooling curve can be plotted to show how fast hot water in a test tube cools.

May/June 2015

Fig. 3.1 shows a metal coffee cup resting on a metal warming plate. A small electrical heater is fitted inside the warming plate, making the plate hotter than the coffee.

May/June 2017

A student examines how three different insulating materials affect the cooling of hot water in a beaker. The apparatus available is: thermometer; stopwatch; 250 cm$^3$ glass beaker; 250 cm$^3$ measuring cylinder; cardboard; cotton wool; cloth; boss, clamp and stand. Hot water is also supplied. Write a plan for the experiment.

May/June 2017

Fig. 10.1 shows a soldering iron. Solder is an alloy of metals used to make a permanent contact between electrical wires. The heating element increases the temperature of the metal tip. When solder is placed against the tip, it melts and flows over the wires to be joined. As the solder cools, it solidifies and the permanent connection is formed. The working temperature of the metal tip is $380\,^{\circ}\text{C}$.

May/June 2019

A student carries out an investigation to determine whether cotton wool or bubble wrap is the better insulator. She is given the following apparatus: a $100\,\text{cm}^{3}$ glass beaker, a supply of hot water, a rectangular piece of cotton wool, a rectangular piece of bubble wrap, adhesive tape.

May/June 2019

Fig. 2.1 shows a hollow metal cube that is filled with boiling water. The temperature of the four vertical surfaces is the same, but each surface has a different colour or texture. Fig. 2.1 shows a metal cube with one shiny white face, a thermal radiation sensor and a meter. A thermal radiation sensor is kept at the same distance from each face, and the meter reading is used to measure the thermal radiation emitted by each one.

May/June 2021

A house is going to be insulated thermally so that thermal energy loss is reduced and fuel costs are lowered. Which type of thermal insulation recovers the installation cost in the shortest time?

May/June 2023

A student examines how quickly hot water cools inside a test-tube in a range of different conditions.

May/June 2024

A copper saucepan fitted with a wooden handle contains cold water. It is set on a heating element that is glowing red hot as part of an electric cooker. Fig. 4.1 illustrates the saucepan resting on the heating element.

Oct/Nov 2015

Which statement concerning the transfer of thermal energy is correct?

Oct/Nov 2016

A student is examining how insulation affects the cooling rate of hot water in a beaker. He pours $250\text{ cm}^3$ of hot water into a beaker and inserts a thermometer into the water, as shown in Fig. 2.1. He waits for a brief period. He then starts a stopwatch as he measures the temperature $\theta$ of the hot water. This is at time $t = 0$. Fig. 2.2 shows the thermometer at $t = 0$.

Oct/Nov 2017

Fig. 9.1 shows the layout of a water cooler that provides cold water for workers in a hot office.

Oct/Nov 2019

A student is studying how fitting a lid changes the rate at which hot water in a beaker cools. • She transfers $200\,\text{cm}^3$ of hot water into a beaker. • She puts a thermometer into the water, as shown in Fig. 4.1. • She leaves it for a brief period. • She notes the water temperature and, at the same moment, starts a stopwatch. This is at time $t = 0$. Fig. 4.2 shows the thermometer at time $t = 0$.

Oct/Nov 2020

Copper is occasionally selected as the material for pans used to heat liquids. A copper pan has water at room temperature in it.

Oct/Nov 2022

A student carries out an investigation into how water cools. The apparatus is shown in Fig. 2.1.

Oct/Nov 2022

During a camping trip, a student cools a sealed bottle of water that is at the same temperature as the surrounding air. Which method cools the water at the highest rate?

Oct/Nov 2023

A metal kettle is placed on a grid over red-hot glowing coal and heated. Which are the principal thermal energy transfers through the base of the kettle and inside the water?

Oct/Nov 2023

A student examines how rapidly water cools near the top and near the bottom of a beaker of hot water. The apparatus setup is shown in Figs. 2.1 and 2.3.

Oct/Nov 2023

Fig. 3.1 depicts a laboratory freezer. Its door is shut and the freezer is on. A cold liquid is pumped along the copper pipe at the top of the freezer. The air beside the copper pipe cools rapidly.

Oct/Nov 2024

Water is heated in a glass beaker from room temperature until it reaches its boiling temperature. Plan an experiment to find out whether the time taken for the water to reach boiling depends on the diameter of the water surface exposed to the air.

Oct/Nov 2024

There are four metal cans that are the same apart from the colour and the texture of their outer surfaces. $100\,\text{cm}^3$ of water at $70^\circ\text{C}$ is poured into each can. Which can cools down most quickly?

Oct/Nov 2025

Fig. 3.1 shows a small block of ice at 0^{\circ}C together with a plastic cup containing 0.24 kg of water. Diagram labels: block of ice, plastic cup, water. At the start, the water in the cup is 22.0^{\circ}C. The block of ice is placed into the water.

Oct/Nov 2025

A student is studying how quickly hot water cools in a beaker. Plan an experiment to explore how the thickness of cardboard insulation around the beaker affects the cooling rate of the hot water in the beaker. The apparatus available includes a supply of hot water, a beaker, a thermometer, and 1 mm thick cardboard sheets.

Oct/Nov 2025