1A student drew a force-extension graph for a sample of metals. She subjected the sample to a force that increased to a maximum and then decreased to zero. When the sample contracts it follows the same force-extension curve as when it was being stretched. What is the behaviour of the metal between S and T?

A metal wire had a tension F and extension x with a Young modulus of E; the wire obeyed Hooke’s law.

Which expression represents the elastic strain energy stored in the wire?

Which of the following is the correct definition of elastic and plastic behaviour?

The graphs below all show force-extension graphs; they are all drawn to the same scale.

Which graph shows the object that has been deformed and has the greatest amount of elastic potential energy?

A spring is extended with varying forces; the graph below shows the results. What is the energy stored in the spring when the extension is 30 mm?

A force compresses a mattress spring by 100 mm. The graph shows the effect of force F on the length l of the string. What is the energy stored in the spring when the length is 70 mm?

A spring is extended due to a force. The graph shows the effect of changing force on the extension of the spring. What is the elastic potential energy of the spring with a force of 8.0 N?

The diagram shows four water molecules in a swimming pool. It also shows how much energy each molecule has. Which of the water molecules is most likely to evaporate from the liquid?

A popular demonstration of kinetic theory is to view smoke particles through a microscope while illuminating them with a bright light.        

The diagram shows the view of the smoke particles through a microscope. They are moving about randomly. What causes the motion of the smoke particles?

Air is trapped inside a cylinder. The volume of the cylinder cannot change. The temperature of the air is increased. Which of the graphs below shows the correct relationship between pressure and temperature?

A whale takes a breath at the surface of the ocean, where the pressure is 1.00 x 10⁵ Pa. It then dives to a depth where the pressure is 1.21 x 10⁵ Pa. The temperature is the same at this depth as it is at the surface. The whale let out a bubble of air of volume 50 cm³. This bubble rises to the surface of the ocean. What is the volume of the bubble when it reaches the surface?

A sealed yet empty (except for air) plastic drinks bottle is left outside in the sunshine on a warm day.

Which row of the table correctly describes what happens to the average speed of the air molecules, and to the pressure inside the bottle?

A syringe is half filled with air and sealed. The plunger is then pulled outwards, causing the volume of the gas to increase. This is done slowly so that the expansion happens at a constant temperature.

What happens to the pressure of the gas, and to the speed of the air molecules?

A sealed piston is used to expand a gas. No gas escapes during the process. What happens to both the density of the gas and to its pressure when it is expanded in this way?

A car tyre is inflated with air.

 As the car drives, the temperature of the tyre increases, which also causes the temperature of the air inside the tyre to increase. This increases the pressure of the air inside the tyre.

 Which of the following is a correct explanation as to why?

A substance is cooled. The graph below shows how its temperature changes over time. What is happening in the portion of the graph labelled XY?

What are the upper and lower fixed points on a Celsius scale thermometer?

Wooden barrels are often reinforced by putting tight iron rings around them. What procedure would make it easier to get the iron ring onto the barrel?

Drinks are often cooled by putting ice cubes into them. A delicious cocktail is initially at a temperature of 12 ⁰C, when a few ice cubes are put into the drink. After some time has passed, some of the ice has melted, and the temperature of the cocktail has dropped to 7⁰C.

What is the temperature of the remaining, unmelted ice?

A pan containing 0.750 kg of water which is initially at 13 ⁰C is heated by an electric hob. 35 kJ of thermal energy is put into the water and its temperature rises. You can assume that all the energy supplied by the hob goes into raising the temperature of the water. The specific heat capacity of water is 4200 J/kg⁰C. To the nearest ⁰C, what is the final temperature of the water?

A laboratory liquid-in-glass thermometer is shown in the diagram below. A manufacturer wants to make a more sensitive thermometer than the one shown. What could be done to achieve this?

An unknown substance is heated in a very controlled way by an electric heater, which supplies 1 kW of power to the substance. The substance changes from a liquid to a gas. The mass of the substance is 650 g.

The graph shows how the temperature of the substance changes with time. What is the specific latent heat of vaporization of the substance?

A substance, which is initially in its solid form, is heated at a constant rate.

      The graph shows how its temperature changes with time. Between which points is the substance partly a liquid and partly a gas?

A National Grid engineer connects an electrical cable between two pylons.  The cable is a bit too tight. What could happen to the wire if the weather became very cold, and why?