Question 1 P = ρgh = (1000)(10)(3) = 30 000 Pa = 3 × 10 4 Pa No. Same level will have the same pressure.
Question 2 Archimedes’ Principle. to withstand the strong water pressure below the sea surface. Volume of submarine, V = 300 m3 (¼)V need to be pumped so that the submarine can submerged in the water.
Question 2 cont… Volume needed to be pumped, r = (1/4) V = (1/4) (300) = 75 m3 Mass of water, m = ρr = (1.2 × 103)(75) = 90 000 = 9 × 104kg
Question 3 A thumbtack. The thumbtack has a very small area of contact compare to the coin. P = F/A = (6) / (5.2 × 10-4) = 1.15 × 10 4 Pa
Question 4 The distance between two adjacent wave fronts. The wavelength are the same. Diagram P Straight wavefronts with a bent at the edge. Diagram Q The wavefronts are semi-circular.
Question 4 cont… If the wavelength is longer/greater than the width of the gap, the diffracted waves are semi-circular. If the wavelength is shorter than the width of the gap, the diffracted waves are straight waves. Diffraction
Question 5 R2 and R3 R1 parallel to R2 and R3 2.0 A 2.0 A
Question 5 cont… R1 R3 R2 1/ R eff = 1/R1 + 1/(R2 + R3) = 1/3 + 1/(2+1) = 2/3 R eff = 3/2 Ω V = IR = 4 ( 3/2) = 6 V
Question 6 cont… Resistance Avoid parallax error while taking the measurement of the voltmeter and the ammeter. or make sure the wire connection is tight.
Question 7 A wave transfer energy from one point to another. A transverse wave is a wave whose particles vibrate perpendicularly to the direction of travel of the wave. 2 λ = 8 λ = 4 cm
Question 7 cont… v = fλ = (5)(4) = 20 cms-1 1. The speed is uniform. 2. Wave travels in a straight line.
Question 7 cont… . The change of speed of the water waves. or The change of depth.
Question 8 Kelvin, K kg m-1 s-2 P is directly proportional to T 1. volume 2. mass Pressure law. Interpolation. 500 K
20 marks Answer one question only Section B
Question 9 The specific heat capacity is the quantity of heat energy required to increase the temperature of 1 kg of the substance by 1°C. 1. Temperature of water in diagram 10.1 equal to temperature of water in diagram 10.2
Question 9 cont… The number of eggs in diagram 10.2 is more than in diagram 10.1 The heat needed to prepare four half-boiled eggs is bigger than for preparing two half-boiled eggs. Mass of water in diagram 10.2 is more than in diagram 10.1
Question 9 cont… Heat supplied to eggs in diagram 10.2 is bigger than heat supplied to eggs in diagram 10.1 The bigger the mass of an object, the bigger the heat capacity of the object.
Question 9 cont… Suitable cooling agent : water Reasons: It is not corrosive It has a high specific heat capacity It can absorb large amounts of heat energy. It is cheap and easily available.
Question 9 cont… Base of the kettle -made of copper, with higher density and a low specific heat capacity. -The kettle is more stable and can get hot quickly. Body of the kettle -made of aluminum, with a lower density and a low specific heat capacity -The kettle is lighter and can get hot quickly
Question 9 cont… Handle of the kettle -made of plastic with high specific heat capacity. -The handle will not get hot too fast
Question 10 simple barometer -water vaporizes at low pressure -water wets the glass tube -column of the tube will be 10 m P = ρgh = (1.36 × 104)(10)(760 × 10-3) = 1.03 105 Nm-2
Question 10 cont… Air pressure in Genting Highland is less than in Kuala Lumpur. From P = ρgh, when P is lower the height of the mercury column is also lower. Thus, the mercury column is lower in Genting Highland and higher in Kuala Lumpur.
Question 10 cont… use Boyle’s Law P1V1 = P2V2 (76 cm Hg)(12cm) = (76 cm Hg + 5 cm Hg) V2 V2 = 11.26 cm P1V1 = P2V2 (76)(12) = (76 – 5) V2 V2 = 12.85 cm
Question 10 cont… Use Charles Law V1/T1 = V2/T2 12 / (273 + 30) = V2 / (273 + 43) V2 = 12.51 cm
Question 10 cont… The increase in temperature cause the kinetic energy to increase. The rate of gas molecules bombarding the wall of the container will increase. According to Charles’ Law, when the pressure is kept constant, the increase in temperature cause the volume to increase.
20 Marks Answer all question Section C
Question 11 Effective resistance, The total resistance of all the resistor when connected in series and parallel. 1/Reff = 1/3 + 1/(4+2) Reff = 2 Ω