---

---

1

A ball of mass 130 g is launched from the ground at an initial velocity of 14 m / s vertically upwards. It decelerates until it is at rest momentarily at a height h above the ground. Define deceleration. The acceleration of free fall is 9.8 m / s2. Show that the time taken for the ball to reach height h is 1.4 s. Ignore the effect of air resistance. Calculate h. Ignore the effect of air resistance. h = The ball is dropped from the top of a tall building. Describe and explain the motion of the ball as it falls. Consider the effect of air resistance in your answer.

1. Motion, forces and energy  →  1.2. Motion

1. Motion, forces and energy  →  1.3. Mass and weight

Open

2

shows solar-powered traffic warning lights. solar cell lights The energy from the solar cell is stored in a battery. Name the energy store in the battery. The two lights in are connected in parallel. State one advantage of a parallel connection in a lighting circuit. The efficiency of the solar cell is 22%. The power supplied to the lights by the cell is 15 W. State what is meant by 22% efficiency. Calculate the solar power input to the solar cell. power = Suggest two advantages of using a solar cell to power the traffic warning lights in compared to using mains electricity.

1. Motion, forces and energy  →  1.7.3. Energy resources

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

Open

3

shows two children balanced on a seesaw. A seesaw is a length of wood which rotates about a central pivot. 450 N 900 N child B child A pivot 1.60 m 0.80 m Child B moves 0.050 m further away from the pivot. Explain why the seesaw rotates clockwise. Child A puts on a backpack and the seesaw now balances. Calculate the mass of the backpack. mass = kg The concrete floor under the seesaw is replaced with a rubber floor. A child falls from the seesaw and experiences an impulse when they hit the floor. Define impulse. Explain how the rubber floor reduces injury to the child. Use ideas about impulse, force, momentum and time in your answer.

1. Motion, forces and energy  →  1.6. Momentum

1. Motion, forces and energy  →  1.5.2. Turning effect of forces

Open

4

shows a stainless-steel saucepan being heated on an electric cooker. The saucepan contains water. State what happens to the water particles as the water temperature increases. The saucepan contains 250 cm3 of water. The specific heat capacity of water is 4200 J / (kg °C). The density of water is 1000 kg / m3. Show that the mass of the water in the saucepan is 0.25 kg. Calculate the energy required to increase the water temperature from 20 °C to 65 °C. energy = The heater supplies enough power to heat the water in 39 s. A student measures the time taken to heat the water as 115 s. Suggest why the actual time taken to heat the water is longer. Assume that the student takes accurate measurements. The stainless-steel saucepan is replaced with an aluminium saucepan of the same mass. It contains the same volume of water. The specific heat capacity of stainless steel is 500 J / (kg °C). The specific heat capacity of aluminium is 890 J / (kg °C). Explain how using an aluminium saucepan will affect the time taken to heat the water.

2. Thermal physics  →  2.2.2. Specific heat capacity

Open

5

shows two containers, each filled with hot water. metal water non-metal water The outer surface of the metal container is hot. Explain how electrons transfer thermal energy through the metal of the container. The outer surface of the non-metal container is much cooler than the outer surface of the metal container. Explain why a non-metal conducts thermal energy less well than a metal. Explain, in terms of particles, why gases are poor thermal conductors compared to non-metal solids.

2. Thermal physics  →  2.3.1. Conduction

Open

6

shows a thin converging lens used to produce a magnified image of an object AB. F1 A B F2 principal axis Explain the meaning of the terms principal focus and focal length. principal focus focal length On , draw the magnified image of AB. Show your working.

3. Waves  →  3.2.3. Thin lenses

Open

7

shows two charged metal plates. X marks the position of the centre of the space between the plates. + + + + + X + + + + – – – – – – – – – positively charged plate negatively charged plate On , draw at least four field lines to show the pattern and the direction of the electric field between the two charged plates. Describe the effect on a negatively charged particle placed at X. During a thunderstorm, an electric field is set up between a cloud and the ground. Charges on the cloud and on the ground are shown in . _ _ _ _ _ + + + + + + path of lightning cloud ground The lightning shown in discharges a current of 28 000 A for 0.0012 s. Calculate the charge that flows from the cloud to the ground. charge = The lightning transfers 1.2 × 108 J of energy. Calculate the potential difference between the base of the cloud and the ground. potential difference =

4. Electricity and magnetism  →  4.2.1. Electric charge

4. Electricity and magnetism  →  4.5.4. Force on a current-carrying conductor

Open

8

shows images produced during two different medical scanning procedures. ultrasound scan of a fetus X-ray scan of a hand Define ultrasound. State how the speed of sound in liquid compares to the speed of sound in air. X-rays are part of the electromagnetic spectrum. State the speed of X-rays in a vacuum. Describe three similarities or differences between the use of ultrasound and X-rays in medical scanning procedures.

3. Waves  →  3.4. Sound

Open

9

shows a mobile phone (cell phone) being charged on a wireless charging plate. primary coil in charging plate secondary coil in mobile phone When the charging plate is switched on, there is an alternating current (a.c.) in the primary coil. A secondary coil is in the mobile phone. Explain how a current is produced in the secondary coil. The maximum energy stored in the battery of the mobile phone is 0.012 kW h. Show that this maximum energy is 4.3 × 104 J. The charging plate in has a useful output power of 15 W. The phone manufacturer claims that the battery can be charged to 50% capacity in less than 30 minutes. Show that this claim is true.

4. Electricity and magnetism  →  4.5.6. The transformer

4. Electricity and magnetism  →  4.2.5. Electrical energy and electrical power

Open

10

Leaks in underground water pipes are detected using radioactive tracers. shows a radiation detector above a water pipe. counter detector leak pipe ground Before the radioactive tracer is added to the water, the detector measures the background radiation above the pipe. The average background radiation is 26 counts / minute. Define background radiation. Suggest one source of radiation that may make a significant contribution to the background count rate. A radioactive tracer is added to the water. The counter in shows the count rate in counts / minute above the leak in the water pipe. Determine the count rate due to the tracer. count rate = Suggest which radioactive emission, alpha, beta or gamma, is suitable for detecting the leak in the water pipe. Explain your answer. emission explanation Explain why the radioactive isotope must not have a very short half-life. Explain why the radioactive isotope must not have a very long half-life.

5. Nuclear physics  →  5.2.1. Detection of radioactivity

Open

11

A galaxy is approximately 1.2 × 1026 m from the Earth. Scientists observe light from the distant galaxy. The wavelength of the observed light is longer than the wavelength of the light emitted from the galaxy. State the name of this effect. State the current estimate for the Hubble constant H0. H0 = Calculate the speed at which the galaxy is moving away from the Earth. speed = Scientists have measured the speeds at which distant galaxies are moving away from the Earth and their distances from the Earth. These measurements suggest that all the Universe was once at a single point. Explain why.

6. Space physics  →  6.2.3. The Universe

Open