Physics 0625/43 October/November 2025: question paper and mark scheme

Question

(a) A hard ball is dropped vertically downwards. Fig. 1.1 shows the speed–time graph for the ball from when it is dropped until it hits the ground. Air resistance is ignored. 8 6 speed 4 m/s 2 0 0 0.2 0.4 0.6 0.8 1.0 time / s Fig. 1.1 (i) Describe the motion of the ball in Fig. 1.1. …… [1] (ii) Show that the distance travelled by the ball is 1.8 m. [2] (iii) The mass of the ball is 0.54 kg. Calculate the gravitational potential energy stored in the ball immediately before it is dropped. gravitational potential energy = …… [2] * 0000800000003 * DFD 3 (iv) Determine the kinetic energy of the ball when it has fallen half way to the ground. kinetic energy = …… [1] (b) The same ball is dropped from an aeroplane. Air resistance acts on the ball. Explain how the vertical motion of the ball changes, from when it is dropped to just before it hits the ground. Use the idea of forces in your answer. …… [3] (c) A soft ball is dropped by a student so that it bounces on the ground. Fig. 1.2 shows the height–time graph for the ball. The height is measured from the ground. The ball bounces four times. A height C m B time / s Fig. 1.2 Explain why the change in height of the ball between B and C is less than the change in height between A and B. …… [2] [Total: 11] * 0000800000004 * DFD 4

Question

A cricket ball is travelling at a speed of 25 m / s horizontally through the air. The mass of the ball is 0.14 kg. A player catches the ball and the ball comes to rest. (a) Calculate the change in momentum of the ball during the catch. change in momentum = …… [2] (b) The player’s hands are in contact with the moving ball for 9.7 ms. Calculate the horizontal force exerted by her hands to bring the ball to rest. force = …… [3] [Total: 5] * 0000800000005 * DFD 5

Question

(a) Fig. 3.1 shows a Sankey diagram for the power transfer in a coal‑fired power station. useful power input power from fuel output = 3400 MW power wasted power power used in power used in in station due to power transmission thermal station = 25 MW energy = 40 MW transfers = 2200 MW Fig. 3.1 (i) Show that the useful power output from the power station is approximately 1100 MW. [2] (ii) Calculate the efficiency of the power station. efficiency = …… [2] (b) Describe how useful energy may be obtained from geothermal resources. …… [2] [Total: 6] * 0000800000006 * DFD 6

Question

(a) (i) A rectangular glass tank contains 3.0 m3 of liquid. The mass of the liquid is 2800 kg. Calculate the density of the liquid. density = …… [1] (ii) A metal block is placed in the tank and it sinks to the bottom. The top surface of the block is 1.1 m below the surface of the liquid. Fig. 4.1 shows the block on the bottom of the tank. liquid 1.1 m metal block 0.30 m 0.45 m Fig. 4.1 Calculate the force exerted by the liquid on the top of the block. force on top of the block = …… [4] * 0000800000007 * DFD 7 (b) Fig. 4.2 shows part of a steel railway track. There are small gaps between sections of the rail. small gap section of rail Fig. 4.2 State why gaps are needed between the sections of rail. Explain your answer in terms of particles. statement …… explanation …… [2] (c) Fig. 4.3 shows a saucepan of boiling water on the heating ring of an electric cooker. boiling water plastic handle metal pan heating ring Fig. 4.3 The handle is made from plastic. Explain why this material is suitable. …… [2] [Total: 9] * 0000800000008 * DFD 8

Question

(a) (i) Electromagnetic waves have many uses. On Fig. 5.1 draw one line from each use to the region of the electromagnetic (e‑m) spectrum it uses. Use Region of e‑m spectrum security marking gamma rays Bluetooth ultraviolet optical fibres infrared detection of cancer radio waves Fig. 5.1 [2] (ii) State one advantage of using microwaves compared with radio waves to transmit mobile (cell) phone signals. …… [1] (b) Describe the difference between transverse waves and longitudinal waves. …… [2] * 0000800000009 * DFD 9 (c) Fig. 5.2 shows a simplified diagram of seismic P‑waves travelling through the Earth. The paths of the waves are curved. Seismic waves are produced by rock movements in earthquakes. earthquake occurs here P-waves (mostly) solid mantle X liquid outer core inner core Fig. 5.2 (not to scale) (i) State the type of wave that P‑waves can be modelled as. …… [1] (ii) At point X, the P‑wave travels from the solid mantle to the liquid core. There is a sudden change in direction of the path of the wave. Explain the change in direction of the P‑wave at point X. …… [2] (d) The Earth’s surface absorbs incoming radiation from the Sun and also emits thermal radiation from its surface. Over the past 50 years, scientists estimate that the average temperature of the Earth’s surface has increased by approximately 0.75 °C. Explain what is causing this average temperature rise. …… [2] [Total: 10] * 0000800000010 * DFD 10

Question

(a) Fig. 6.1 shows a circuit which includes an LDR (light‑dependent resistor). 400 Ω + +5.0 V ı V Fig. 6.1 The LDR is in a brightly lit room. The voltmeter reads 1.8 V. (i) Calculate the current in the 400 Ω resistor. current = …… [3] (ii) The light level in the room changes from bright to dark. State and explain the effect on the voltmeter reading. statement …… explanation …… [3] * 0000800000011 * DFD 11 (b) Fig. 6.2 shows two light‑emitting diodes (LEDs) connected in parallel in a circuit. R is a red LED and G is a green LED. The voltmeter across the LEDs shows a potential difference (p.d.) of 2.0 V. A + +5.0 V ı R G V 2.0 V Fig. 6.2 (i) Fig. 6.3 shows a current‑p.d. graph for the LEDs. R G 80 60 current 40 mA 20 0 0 1.0 2.0 3.0 4.0 p.d./ V Fig. 6.3 Use Fig. 6.3 to determine the current in the ammeter. current = …… [2] (ii) The connections to the power supply are reversed. State the reading on the ammeter. current = …… [1] [Total: 9] DFD 12 * 0000800000013 * DFD 13

Question

Fig. 7.1 shows a simple a.c. generator. handle coil N S slip rings coil brush front Fig. 7.1 (a) (i) Explain the function of the slip rings and brushes. …… [1] (ii) Describe how an alternating current is generated in the lamp. …… [3] (iii) State two possible changes that cause a larger maximum current in the lamp. 1 …… 2 …… [2] * 0000800000014 * DFD 14 (b) Fig. 7.2 is a graph to show how the electromotive force (e.m.f.) varies with time for the coil. e.m.f. 0 0 A B C D E time Fig. 7.2 (i) Determine how many revolutions the coil has made, from time = 0 to E. number of revolutions = …… [1] * 0000800000015 * DFD 15 (ii) Fig. 7.3 shows the end view of the position of the plane of the coil at time = 0. The coil is rotating anti‑clockwise. coil N S axis of rotation slip rings Fig. 7.3 On Fig. 7.4, draw four lines to match the coil position to the times A, B, C and D. The coil is viewed from the front. Each coil position may be used once, more than once or not at all. time label coil position from graph A N S B N S C N S D N S Fig. 7.4 [3] [Total: 10] * 0000800000016 * DFD 16

Question

(a) Alpha (α) particles are directed at a very thin sheet of gold foil. The following observations provide evidence for the nuclear model of the atom. State what conclusions may be made about the model of the atom from these observations. (i) Observation: most of the particles pass straight through the foil. conclusion …… …… [1] (ii) Observation: a few particles bounce back or are deflected through large angles. conclusion …… …… [1] (b) Fig. 8.1 shows three beams of ionising radiation, alpha, beta and gamma, passing between two parallel plates. The plates are charged and there is a uniform electric field between them. charged plate P Q R charged plate Fig. 8.1 (i) State and explain which path P, Q or R shows a beam of alpha particles. path …… explanation …… [2] * 0000800000017 * DFD 17 (ii) State and explain the direction of the electric field between the plates. direction …… explanation …… [1] (c) Curium‑242 is a radioactive isotope. It emits alpha particles. It has a half‑life of 160 days. After 480 days, the mass of curium‑242 in a sample is 2.4 × 10–3 g. Calculate the initial mass of curium‑242 in the sample. initial mass of curium‑242 = …… [2] [Total: 7] * 0000800000018 * DFD 18

Question

(a) Cosmic microwave background radiation (CMBR) can be observed in every direction in space around us. (i) State when CMBR was produced. …… [1] (ii) State and explain how the wavelength of this radiation has changed since it was formed. …… [2] (b) Table 9.1 shows data about planets in our solar system. Table 9.1 average radius of average surface time for one orbit / planet orbit around the Sun / temperature / Earth years 106 km °C Venus 108 0.62 460 Earth 150 1.00 15 Mars 228 1.90 – 65 Jupiter 778 12.00 –110 Saturn 1430 29.00 –140 (i) The orbit of Venus is approximately circular. Calculate the average orbital speed v of Venus. Give your answer in km / h. orbital speed = …… km / h [3] (ii) State how the average surface temperature of a planet changes as its distance from the Sun increases. …… [1] [Total: 7] * 0000800000019 * DFD 19

Question

(a) Sketch a diagram to show the orbital path of a comet around the Sun. Mark the position of the Sun on your diagram using an S. [2] (b) Draw a cross on your diagram to show where the comet is travelling with the slowest speed. Label the cross L. [1] (c) Explain why the speed of a comet changes as it travels around its orbit. Use the conservation of energy in your explanation. …… [3] [Total: 6] * 0000800000020 * DFD 20