MFSS Prelim P1 Ans

- Page 1 - 2024 O-Level Prelim Physics 6091/01 Solution [40m] 1 D 2 B 3 D 4 B 5 B 6 B 7 A 8 C 9 C 10 C 11 C 12 C 13 B 14 B 15 D 16 A 17 B 18 D 19 D 20 C 21 B 22 C 23 B 24 D 25 B 26 A 27 A 28 D 29 D 30 D 31 A 32 B 33 B 34 C 35 C 36 B 37 D 38 B 39 B 40 C 5 B 11 C Taking pivot at F, 50 W = 75 P P = 50/75 W = 2/3 W 12 C Volume of shaded = 1 cm3 Mass of shaded = 6 g Volume of unshaded = 2 cm3 Mass of unshaded = 18 g Total mass/total volume = 24/3 14 B Change of volume is constant 6x = 1 (0.8) 20 C 22 C 23 B Refraction takes place. Nwater > Nair

- Page 2 - Vwater<Vair Frequency no change. 24 D v = 2d/t 1500 = 12000/t t = 8.00 s (time for pulse emit and receive) 8 + 2 = 10.0 s 26 A v=fλ f low, then λ is high 32 B W = QV = 90 x 3 x 1010 12024 O-Level Prelim Physics 6091/02 Solution [80m] Section A: Answer All Questions (50 + 10 (LQ) + 10 (Data) Marks) 1 ai a=∆୴∆୲ or a ୴ି୳୲ (2 points to be as wide as possible) or (58 – 50) / 0.20 (if lenient) any value from 35.0 to 43.0 m/s2 (3sf + SI unit) 𝐚 =𝐯𝐭 𝒎𝒆𝒂𝒏𝒔 𝟏 𝒑𝒐𝒊𝒏𝒕 𝒅𝒊𝒗𝒊𝒅𝒆𝒅 𝒃𝒚 𝟏 𝒑𝒐𝒊𝒏𝒕. 𝑰𝒕 𝒊𝒔 𝒂 𝒘𝒓𝒐𝒏𝒈 𝒇𝒐𝒓𝒎𝒖𝒍𝒂 𝒕𝒐 𝒖𝒔𝒆. 1 1 aii Taking upward resultant force as positive, FR = FA – W 1m for FR = ma ma = FA – mg FA = ma + mg = 76 x 40 + 76 x 10 and (students to transfer a from 1ai correctly) = 3800 N 1 1 1 b (deceleration because) upward force greater than weight or upward resultant force air resistance decreases (with decreasing speed / with time) or deceleration decreases or resultant (upward) force decreases B (until / finally) weight equals air resistance or forces balance or at terminal / constant velocity / speed 1 1 1 W FA

- Page 3 - 2 ai Since gravitational field strength decreases as object moves further from the planet, OR and because gravitational field strength is the greatest when Pluto is at X and AND therefore, speed decreases from X to Y. As gravitational field strength increases as Pluto moves from Y to X, therefore speed increases from Y to X 1 1 aii Since energy cannot be created or destroyed or energy can be transferred to one energy store to another, and because some energy in the gravitational potential store is transferred to kinetic store as Pluto moves from Y to X, therefore speed increases when Pluto moves from Y to X. 1 1 b (white surface) is a poor absorber / good reflector / poor emitter of IR / radiation OR black / other surface is a good absorber / poor reflector / good emitter of IR / radiation any one from:  (the white surface) increases in temperature less when facing the Sun  (the white surface) decreases in temperature less when facing away (from Sun)  the black / other surfaces increases in temperature more when facing the Sun  the black / other surface decreases in temperature more when facing away 1 1 3 a Since pressure is force per unit area, and because, the person is spread over a greater co