2024 CCHM Physics 6091 P1 & P2 (MS)

Answers 1a uniform / constant acceleration for 6.0 s B1 after 6.0 s zero acceleration Reject: constant speed / velocity B1 1b m = F / a OR m = Ft / Δv in any form i.e. m = 1880 (6.0) / (22.0 – 0) C1 m = 513 kg A1 1c s = area under graph numerical or algebraic i.e. s = ½ (3.0 + 9.0) x 22 C1 s = 132 m A1 1di rising of hot air / fluid and sinking of cold air / fluid OR circulation of air / fluid due to / with temperature differences B1 1dii High temperature spot on Earth OR Sun heats surface OR (hot) less dense air rises upwards B1 2a lamina is in the Earth’s gravitational field OR Earth exerts a gravitational force on lamina Accept: gravitational field strength B1 2bi M = F  ┴ d OR 0.040(10) x 0.08 OR 0.4 x 8 C1 0.032 Nm OR 3.2 N cm A1 2bii lamina moves clockwise (about the pivot) B1 it speeds up and then slows down OR it oscillates with decreasing amplitude B1 stops with G vertically / directly below H / pivot / nail B1 3ai mercury stops exerting a pressure / weight per unit area on gas when tube is horizontal B1 3aii All 3 points mentioned B2, 1 or 2 point(s) mentioned B1 • The gas particles are in continuous, random motion at high speeds. • They collide with the tube walls, exerting an (average) force on the wall. • The average force per unit area exerted by these gas particles give rise to pressure. B2 3b P= ρgh OR 40 800 seen i.e P = 13600 x 10 x 0.30 C1 Total pressure = 40 800 + 101 000 =142 000 Pa A1

4ai chemical (potential store) B1 4aii Energy transferred by (electrical) current / electrically (from chemical store of battery to kinetic store of motor) OR electrons (made to) move B1 work is done mechanically by the motor on the (back) wheel OR Energy is transferred mechanically from motor to (back) wheel B1 4b KE = ½ mv2 in any form i.e. KE = ½ (800/10)(5.5)2 C1 1210 J A1 4ci energy provided when power is 1 kW for 1 hour / 1000 W for 1 hour B1 4cii t = E / P OR 0.45 / 0.075 OR 450 / 75 C1 6.0 h A1 5ai ∆E = mc ∆  in any form i.e. E = 0.500 x 4200 x 3.5 C1 7350 J A1 5aii energy input = 13 x 600 = 7800 J C1 efficiency = useful energy (output) / total energy (input) (  100%) OR (7800 – 7350) / 7800 x 100 C1 5.77% A1 5b any one from: • temperature change is an underestimate due to energy losses • energy is transferred from the water (to air / beaker / bench / surroundings) • energy other than light transferred in lamp (filament / glass / internal structure) AWW: energy loss B1 6ai object within focal length B1 6aii Virtual images are formed from divergent rays OR rays that extend back behind lens to meet at point on image OR rays that do not meet / converge on a screen OR rays that appear to come from image B1 6bi ray through optical centre from top of object B1 ray parallel to axis from top of object to lens AND correctly refracted through lens to appear to come from top of image B1 both rays virtually extended back to image + arrows on real rays B1

6bii 4.0 cm Allow for ½ square (3.8 cm to 4.2 cm) A1 7a electrons move from rod to cloth B1 7bi region where an electric charge experiences a force OR region where a charge experiences an electric force B1 7bii At least three radial field lines distributed evenly around outside of S AND touching S AND not inside S B1 arrow on (at least one) field line pointing towards S B1 7c arrow through X and away from centre of sphere B1 8a horizontal path marked with  and no other path indicated as  B1 8b beta (-radiation) B1 All 3 points mentioned B2, 1 or 2 point(s) mentioned B1 • Fleming’s left-hand rule mentioned • first finger into page AND thumb downwards • second finger which is current opposite to motion (to electron or beta particle) B2 8c beta (-radiation) completely absorbed. Accept: blocked / stopped B1 some gamma rays absorbed OR (some) gamma passes through B1 9a NIR (shortest wavelength = highest frequency = more energy) B1 9b FIR B1 9c Any 1 of the 8 properties listed below. 1. They are transverse waves. 2. They can travel through vacuum. 3. They transfer energy from one place to another. 4. They travel at the speed of 3.0 x 108 m/s in vacuum. 5. They obey the wave equation, v = f λ. 6. They obey the laws of reflection and refraction. 7. They carry no electric charge. 8. When they travel from one medium to another, frequency does not change; only speed and wavelength changes. Reject: Non-ionising B1

9d v = f λ in any form For 3 μm, f = 3.0 x 108 / 3.0 x 10-6 = 1.0 x 1014 Hz For 8 μm, f = 3.0 x 108 / 8.0 x 10-6 = 3.75 x 1013 Hz Correct substitution and working Range: 3.75 x 1013 Hz to 1.0 x 1014 Hz C1 } }C1 } A1 9e If clouds or haze present, photograph will show the clouds and haze which blocks the forest fire spots. B1 IR, on the other hand, can pass through the clouds or haze and an IR image will show the spots (that are red in colour) which are on fire B1 9f Any 2 from • Remote controllers to control a variety of electrical devices • Forehead / Ear thermometers to determine body temperature • Intruder alarms to detect trespasser other acceptable common answers • NIR: Night Vision Goggles for enhance imaging in the dark • SWIR: Long distance telecommunications for used in fibre optics communication • MWIR: Infra-red tracking or homing for guided missiles • LWIR: Thermographic cameras for Thermal imaging & • FIR: Infra-red telescope for astronomy & Infra-red lamp for heat therapy method of physiotherapy (or pain relief) Reject: remote controller only, digital thermometer, radiator, heater & oven B2 10a 9.0 V A1 10b I = V / R OR 9.0 / 900 C1 0.010 A A1 10c 0 A A1 0.010 A A1 10d resistance decreases B1 no change (OR remains at 0) B1 10e sketch: x-axis labelled V and the y-axis labelled I, AND steeper curve from origin curving such that I/V decreases B1 explanation: as current / temperature increases so resistance increases B1 if V on y-axis: gradient must increase OR if V on x-axis: gradient must decrease Accept gradient = I/V ratio B1

11a switch is in the live wire B1 so when switch is off, hifi is disconnected / isolated from mains supply / high voltage (so no risk of electrocution) B1 11bi step-down (transformer) B1 11bii • (soft) iron core • two coils of copper wire OR primary coil AND secondary coil • turns ratio of 20 : 1 OR 240 : 12 owtte OR use of transformer equation Reject: 240V & 12V B3 11ci current repeatedly changes direction B1 11cii magnetic effect of current causes coil to become an electromagnet B1 coil attracted to magnet and repelled by magnet repeatedly / alternately B1 11ciii any values(s) between 20 to 20 000 Hz B1 12ai magnetic field or magnetic flux (from magnets) mentioned B1 sides of coil cut (magnetic) field OR (magnetic) field / flux in coil changes Reject: magnetic field from coil B1 12aii horizontal line, labelled B on the left and A on the right B1 12aiii vertical line, labelled A at top and B at bottom B1 12 aiv horizontal line, labelled A on the left and B on the right B1 12bi one ring (instead of two) with gaps between the two halves C1 each side of split ring connected to a different end of the coil and to a brush A1 12bii magnetic field of coil (due to current) interacts with field of magnet B1 12biii turning effect is greater. Accept motor / coil rotate faster B1 12biv turning effect is less. Accept motor / coil rotate slower B1

1. B 11. D 21. D 31. B 2. A 12. A 22. D 32. C 3. C 13. A 23. B 33. C 4. D 14. D 24. D 34. D 5. B 15. A 25. B 35. D 6. A 16. D 26. D 36. D 7. B 17. A 27. B 37. A 8. C 18. D 28. B 38. B 9. B 19. D 29. A 39. C 10. C 20. D 30. D 40. B