6091/ 01/02 Nov 2024 Suggested Answers (Montfort Sec)

2024 GCE O Level Physics 6091 Propose Answer Paper 2 Section A Qn Answer Comments 1(a) 10 m/s2 B1 CAO 1(b)(i) Speed should be 30 m/s after 3.0 s with g = 10 m/s2 but with a speed of 15 m/s after 3.0 s indicate the presence of air resistance decreasing the rate of change of speed. B1 Must use data. 1(b) (ii) [1] Constant acceleration (straight line) from 0 to 15 for first 3.0 s [1] Ball hits floor and in contact for 0.2 s(3.2 s) [1] From -10 m/s to 0 m/s at 5.0 s [1] gradient should be the same as previous line. 1(c) The area of the velocity- time graph between t = 0 s and t = 3.0 s would give the height. B1

Qn Answer Comments 2(a) Inertia (depends on mass only) 2(b) i 5000 N [1] to the left acting on the road from the car [1] ii F = ma F = 5000 – 3500 = 1500 1500 = ma a = 1500 / 800 = 1.9 m/s2(2sf) C1 B1 iii 3(a) 2.0 cm2 = 2.0 x 10-4 m2 Pressure = Force / area = 60 / (2.0 x 10-4) Pressure = 3.0 x 105 Pa C1 B1 3(b) Oil is an incompressible liquid, hence pressure from piston P is transmitted to piston Q. Piston Q has a wider area than piston P, hence with the same pressure, force at piston Q will be smaller. B1 B1 3(c)i Strong internal forces between molecules of oil as well as closely packed molecules make it difficult for molecules to be compressed. B1 B1 Must describe structure rather than motion. 3(c)ii Some of the energy will be loss to compress the bubbles of air. B1

Qn Answer Comments 4(a)i Work done = force x distance Force = work done / distance Force = 1.6 x 105 / 210 = 760 N (2sf) C1 B1 4(a)ii Speed = distance / time = 210 / 150 = 1.4 m/s Ek = ½ mv2 = ½ x 160 x (1.4)(1.4) = 156.8 = 160 J (2sf) C1 B1 4(b) Non- renewable renewable B1 for non-renewable B1 for renewable nuclear fuel fossil fuels biofuel hydropower geothermal wind 5(a) v = l × f l = v / f = 3.0 x 108 / 2.5 x 109 = 0.12 m C1 B1 5(b)i Radio waves infrared ultraviolet B1 5(b)ii In remote controllers to control equipment/appliances Intruder alarms / thermal imaging B1 5(b)iii Artificial tanning in sunbeds / bank note authentications / disinfecting water/ surgical equipment B1 5(c)i High power radio waves can cause heating of the skin / body tissues, which can cause burns B1 5(c)ii High frequency electromagnetic radiation at low powers can have high ionising effect and can damage cells. Long term exposure may cause cancer. B1 B1 6(a)i [1] for correct rays [1] for correct position of image 6(a)ii The image of the can be obtained by first extending or extrapolating the 2 ray of reflections behind the mirror as virtual rays. The point of intersection between the 2 extended will lie the image. B1

Qn Answer Comments 6(b) Time between pulses = 1/8 = 0.125 s Max distance = ½ (speed x time) = ½ (320 x 0.125) = 20 m B1 C1 B1 7(a) total resistance in parallel = (!"#$!%+!&')-1 = 20 W Total resistance in circuit = 100 W + 20 W = 120 W C1 B1 7(b)i Current in circui