CAT HIGH 2025 PHY PRELIM P1+P2 MS

2025 CHS SEC 4 PHYSICS PRELIMINARY EXAMINATION 2025 CHS Physics Prelim Paper 1 Qn Qn Qn Qn Qn 1 B 2 D 3 D 4 B 5 B 6 B 7 D 8 D 9 D 10 C 11 A 12 B 13 C 14 D 15 B 16 B 17 C 18 C 19 C 20 C 21 A 22 B 23 D 24 B 25 A 26 D 27 C 28 A 29 C 30 B 31 B 32 A 33 B 34 B 35 B 36 D 37 C 38 C 39 C 40 C

2 2025 CHS Physics Prelim Paper 2 Section A S/N Mark Scheme 1ai ● 10 m/s2 [A1] 1aii ● ball moves (downwards) with speed increasing at a constant rate (or with a constant acceleration) [B1] ● moves upwards (or changes direction) with speed decreasing at a constant rate (or with a constant deceleration) until it is instantaneously stationary. [B1] 1aiii ● Distance travelled (vertically) upwards (after first impact with ground) is the same as distance travelled (vertically) downwards (before second impact with ground / after reaching maximum height) [A1] 1bi same gradient at t = 0 and decreasing gradient (cannot be zero) and longer time for first impact with ground and smaller maximum velocity before first impact with ground and velocity becomes zero. [A1] 1bii ● Air resistance increases with speed and is in opposite direction to weight. [M1] ● Resultant force decreases, and hence acceleration decreases (or speed increases at a decreasing rate). [A1]

3 S/N Mark Scheme 2a By principle of moments, Taking moments about pivot, [formula] Sum of clockwise moments = sum of anti-clockwise moments [formula] M = F x d [formula] F x 4.0 cos 50o = 45 x (7.0 + 4.0 cos 50o) [B1] F = 168 N (3 s.f.) [B1] 2b By Newton’s First Law, Sum of downward forces = sum of upward forces Force on pivot + 45 = 168 Force on pivot = 123 N [B1] Direction = downwards [B1] 2c ● At the back, molars apply a force on the food whose line of action has a shorter perpendicular distance to the pivot. [B1] ● For the same moment created by F, force by molar teeth on (hard) food is larger. [B1] 2d ● Incisors have a smaller surface area of contact (with the meat) than molars. [B1] ● (For the same force exerted,) incisors exert a larger pressure to be able to cut meat. [B1] 3ai ● change of internal energy (of a material) per unit mass [B1] ● for each unit change in temperature [B1] 3aii E = mcΔθ [formula] = 2.0 x 460 x (500 – 50) [B1] = 4.14 x 105 J (3 s.f.) [B1] 3b ● air (above the water) expands on heating [B1] ● density of hot air less (than cold air) and hot air rises [B1] ● cold air (being denser) falls (and cycle repeats) [B1] 4a a wave that travels in a direction parallel to the direction of vibration (or oscillation) of particles [B1] 4bi C in correct position i.e. gap 4, 18 or 32 [B1] R in correct position i.e. gap 11 or 25 [B1] 4bii 6.4 cm [B1] 4biii v = f λ = 5 100 x 0.064 (using answer in 4bii converted to m) [B1] = 326 m / s [B1] 4c ● (Sound travels faster in glass th