RI 2023 A-Level H2 Phys Solution

RAFFLES INSTITUTION YEAR 5-6 PHYSICS DEPARTMENT 1 9749 H2 Physics 2023 GCE A-Level Suggested Solutions Paper 1 1 C The varying reaction time of a person will cause him/her to start and stop the stop-watch either early or late giving rise to random error. 2 D Displacement is the area under the v – t graph ( )1 2= + p qr 3 A ( )= = = = 2 2 211 1 22 2 2 mv pE mv mm p mE Average force, ( ) ∆= ∆ −−= = = ⇒∝ 0 2 pF t pF t Ft p Ft mE Ft E 4 C Since collision is elastic, Relative speed of approach = relative speed of separation ( )1 2 21 12 21 −− = − +=− u u vv uu v v 5 B Let the CG be a distance x below the centre of the upper square. Treating the sheet as horizontal and take moments about the CG. ( )0.5 4 24 1.33 mgx mg x xx x = − = − = Hence, it is 6.0 − 1.33 = 4.7 cm Or: ( ) ( ) 11 2 2 12 0.5 2.0 6.0 1.5 4.67 cm cm mx mxx mm mm m += + += =

RAFFLES INSTITUTION YEAR 5-6 PHYSICS DEPARTMENT 2 6 B ( ) ( ) 2 2 2211 10.6 0.6 9 .7 4.0 1.522 2 40.0125 W = ×−= × − = mmP uv tt Option A: 12 1.5 18 W= ×=P Option B: 12 3.3 39.6 W= ×=P Option C: 24 0.60 14.4 W= ×=P Option D: 24 2.8 67.2 W= ×=P 7 C In half a year, Earth will complete half a circle around the Sun. Hence angular displacement is π rad. 8 B Gravitational field strength is gravitational force exerted per unit mass. 9 C For path C, the spacecraft will constantly experience gravitational force due to Earth. Hence it will tend to curve towards the Earth unless the spacecraft fires its rockets to maintain its straight path. 10 A Time duration t for each molecule to hit the same shaded wall again 2p v= ( )( )−−∆= = = = 22 2 N mv mvpF tt Nmv mNv p p v 11 B ( ) 0 273 273 273 273 273 2 ° ° ° ∝ ∴= + = C C C UT U U UU 12 C =P mc t θ For the same P supplied, gradient of temperature-time graph of P (i.e. t θ ) is steeper than that of Q. Hence, c of P will be smaller than that of Q. =Pt mL . Since P took a longer time t, L of P is larger than that of Q. 13 B ( ) 22 222 6 0 23 3 31 1 1 2.9 10 2 2.0 1022 6.02 10 3.0 10 4.2 10 J − − − −  × = × ××  = × mx πω 14 D Phase difference 1 360 1203= × °= ° 2 2 2 3 2.252 ∝ = =X Y AI I I

RAFFLES INSTITUTION YEAR 5-6 PHYSICS DEPARTMENT 3 15 B After 1st filter 0=I After 2nd filter 2 0 cos 45 °=I After 3rd filter 22 00cos 45 cos 45 0.25° °==I I 16 D sinb θλ= Using small angle approximation, tan 2 22 b xb D D cDb x fx θλ λ λ ≈  ≈ ≈= 17 A ( ) 9 63 3 sin 2 500 10 2.0 10 m 2.0 10 mm60sin 2 1lines per mm 5002.0 10 − −− − = × = = ×= × °  = = × n d d λθ 18 A increase linearly with since is increased at a constant rate = ∝ ∴ Dx a xD x t D λ 19 D The beam of protons will be attracted to plate Y (negative plate) and move in a parabolic path as the electric force on them is constant (always downwards). 20 B 0 1 4= ⇒∝QVV rrπε P P 22 636 3 600 V ∴= = V V 21 B Definit