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1

Two athletes, A and B, run a 100 m race. At time t = 0, a gun is fired to start the race. shows the distance-time graph for the two athletes. distance /m time / s A A B B Describe the motion of athlete A during the first 8 s of the race. Examiner’s Use State the distance between the two athletes as the winner passes the 100 m mark. Calculate the speed of athlete A between t = 4 s and t = 15 s. speed =

1. Motion, forces and energy  →  1.2. Motion

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2

Use A student investigates the evaporation of water. He pours 100 cm3 of water into measuring cylinder A and 100 cm3 of water into measuring cylinder B. Measuring cylinder A is kept at 40 °C and B is kept at 80 °C in the same part of the laboratory. shows the two measuring cylinders after 3 days. A kept at 40°C cm3 B kept at 80°C cm3 Using ideas about molecules, explain why more water evaporates when the water is kept at 80 °C. Apart from an increase in temperature, state one change that causes water to evaporate faster. The specific latent heat of vaporisation of water is 2300 J / g and the density of water is 1.0 g / cm3. During the three days, the water level in B drops from the 100 cm3 mark to the level shown in . Calculate the energy used to evaporate water from B during the three days. energy =

2. Thermal physics  →  2.2.3. Melting, boiling and evaporation

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3

Use shows a thermometer. -10 °C Explain how to calibrate a thermometer. State the range of the thermometer in . State how you know that the scale of the thermometer in is linear. shows a thermometer which is more sensitive than the thermometer in . Only 0 °C is marked on this new thermometer. On , draw the temperature markings for 10 °C and 20 °C. °C

2. Thermal physics  →  2.2.1. Thermal expansion of solids, liquids and gases

1. Motion, forces and energy  →  1.8. Pressure

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4

Use shows part of an optical fibre. P glass Q R The ray PQ undergoes total internal reflection in the optical fibre. On , continue the path of ray PQ until it reaches end R. Explain what is meant by total internal reflection. Optical fibres are cheaper and lighter than copper wires. State one other advantage of using optical fibres rather than copper wires for telephone communications. The light in the optical fibre is travelling at a speed of 2.1 × 108 m / s and has a wavelength of 6.4 × 10–7 m. Calculate the frequency of the light. frequency =

3. Waves  →  3.2.2. Refraction of light

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5

Use is drawn full scale. The focal length of the lens is 3.0 cm. On , draw two rays from the top of the object O that meet at the image. Define the term linear magnification. Determine the magnification produced by the lens in . magnification = shows a normal eye viewing an object close to it. is a long-sighted eye viewing an object at the same distance. normal eye long-sighted eye Complete to show the rays travelling through the eye. O lens

3. Waves  →  3.2.3. Thin lenses

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6

Use shows a coil of wire wound on a cardboard tube. There is a d.c. current in the coil. The direction of the current is shown in the key. wire with current into page key wire with current out of page cardboard tube On , draw the magnetic field produced by the coil. shows a simple loudspeaker that uses the coil shown in attached to a paper cone. coil paper cone permanent magnet N S The coil is connected to a signal generator. There is an alternating current of frequency 100 Hz in the coil. State what is meant by a frequency of 100 Hz. Examiner’s Use Describe and explain the movement of the coil.

4. Electricity and magnetism  →  4.5.3. Magnetic effect of a current

4. Electricity and magnetism  →  4.5.5. The d.c. motor

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7

Use shows an electrical circuit containing a 12 V power supply and a number of resistors. 3 Ω 2 Ω 4 Ω 6 Ω 12 V A Calculate the combined resistance of the 2 Ω and 4 Ω resistors in series, resistance = the 3 Ω and 6 Ω resistors in parallel. resistance = Calculate the reading of the ammeter in . ammeter reading = Determine the potential difference across the 4 Ω resistor. p.d. =

4. Electricity and magnetism  →  4.3.2. Series and parallel circuits

4. Electricity and magnetism  →  4.2.4. Resistance

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8

Use Explain how it is possible for an element to have different isotopes. State what is meant by the half-life of a radioactive isotope. shows how the number of atoms of a radioactive isotope changes with time. time / s number of atoms Determine the half-life of the radioactive isotope. On , show how you obtained your result. half-life =

5. Nuclear physics  →  5.2.5. Half-life

5. Nuclear physics  →  5.1.2. The nucleus

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9

shows the horizontal forces acting on a moving car. force A force B Compare the sizes and directions of the two forces when the car is moving along a straight road at constant speed, accelerating. Suggest the direction of the resultant force on the car when the car turns a corner at constant speed. shows the speed-time graph for the first 24 s of the motion of the car along a straight road. time /s speed m/s During the motion there is a period of uniform acceleration. State both the start and finish times of this period. State the main energy changes that occur in the 24 s. Calculate the acceleration of the car during the first 5 s. State clearly the equation that you use. Determine the distance travelled in the first 5 s. The car is stopped by applying the brakes. Various factors can affect the distance travelled by the car during the time that the brakes are applied. Apart from the force applied by the brakes, state two of these factors.

1. Motion, forces and energy  →  1.2. Motion

1. Motion, forces and energy  →  1.7.2. Work

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10

A farmer connects a house to the mains electricity. The house is a long way from the nearest 230 V mains electricity supply. shows the mains supply connected to the house. 230 V mains supply The farmer uses 230 V lamps in the house but they do not light up at full brightness. Explain why the lamps are dim. The farmer adds transformers, as shown in . 230 V mains supply transformer A transformer B The lamps in the distant house light up at full brightness. Explain why the lamps are now bright. Describe the structure of a transformer. You may draw a diagram to help your explanation. Explain in detail how a transformer produces an output voltage. The 230 V mains supply provides 690 W of power to transformer A in . Calculate the current supplied to the transformer. Calculate the energy supplied to the transformer in 10 minutes. Give your answer in joules.

4. Electricity and magnetism  →  4.5.6. The transformer

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11

A plastic rod is rubbed with a cloth and becomes negatively charged. Explain how the rod becomes negatively charged when rubbed with a cloth. An uncharged metal-coated sphere hangs from an insulating thread. The sphere is brought near to the rod. The sphere is attracted to the rod, as shown in . insulating thread metal-coated sphere plastic rod – – – – – – – – point X Describe and explain what happens to the free electrons in the metal-coated sphere as it approaches the rod. Draw a diagram to show how charge is distributed on the sphere. Explain why the uncharged sphere is attracted to the negatively-charged rod. With the charged rod still close, point X on the metal-coated sphere is earthed. State what is meant by earthing the sphere. Describe and explain what happens to the free electrons in the metal-coated sphere as it is earthed. Draw a diagram to show how the charge is now distributed on the sphere. Describe one device where electrostatic charging is used. In your answer include a diagram and explain how and why the charge is produced.

4. Electricity and magnetism  →  4.2.1. Electrical charge

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