HCI Sample B Paper 2

Name: __________________________________ ( ) Class: _____ HWA CHONG INSTITUTION Sample Paper B PHYSICS Paper 2 Level: Secondary Three Duration: 1 hour 45 min Do not open this booklet until you are told to do so. INSTRUCTIONS TO CANDIDATES Write your name, index number and class on the top of this page. Answer the questions in Section A and B in the spaces provided. All workings must be shown. In Section B, for Question 8 answer ‘EITHER’ or ‘OR’. INFORMATION FOR CANDIDATES In Sections A and B the intended marks for each question or part of a question are given in brackets [ ]. Any working should be done in the space provided. When necessary, take g to be 10 m s-2 or 10 N kg-1 ___________________________________________________________________ This question paper consists of 15 printed pages, including this page.

2 SECTION A (40 MARKS) 1) In Oishi Sushi restaurant, after customers had placed their orders via a touch screen menu, shortly after, automated carrie rs would transport the ordered food from the kitchen to them via high speed tracks. After the customers had removed the food from the carriers, they would press a button located at their booths to send the carriers back to the kitchen. Fig. 1.1 shows two such empty carriers A and B on separate tracks at booths 1 and 2 respectively . Both carriers were at rest and directly below the booth buttons. Image source: http://www.canstockphoto.com/illustration/shinkansen.html Fig. 1.1 Fig. 1.2 represents the motion of carriers A and B over a period of 25 seconds. Fig. 1.2 At t = 0 s, carrier A was at the kitchen whereas carrier B was at booth 2. (a) Describe the resultant force acting on carrier A for its journey from the kitchen to booth 1. [3] ………………………………………………………………………………........... ………………………………………………………………………………........... ………………………………………………………………………………...........  to kitchen 1 2 A B high speed tracks buttons Legend: A: B: velocity/m s-1 time/s -0.50 0.50 1.00 0 5.0 10.0 15.0 20.0 -1.00 25.0 30.0

3 (b) Carrier A was transporting a bowl of soup from the kitchen to booth 1. On Fig. 1.3, sketch the soup level if carrier A had (i) moved with constant velocity, [1] (ii) suddenly accelerated from rest. [1] (i) (ii) Fig. 1.3 (c) Both carriers were at rest at booths 1 and 2 during a common time range from t1 s to t2 s. State the values of t1 and t2. [1] ………………………………………………………………………………........... (d) Given carrier B left booth 2 and was directly below carrier A just when it was about to leave booth 1, (i) calculate the distance between the two booth buttons. [2] (ii) determine the magnitude and direction of carrier B's initial acceleration. [2] 2) Fig. 2.1 shows a scale diagram of the paths of light rays from an object point P passing through a thin converging lens L of focal point F. Fig. 2.1 scale 4.0 cm F P L

4 (a) Given the image is 24.0 cm from the lens, on Fig. 2.1, mark out the position of the image and label it I. [1] (b) On Fig. 2.1 , complete the path of the two rays to show how the image I is produced by the lens. Show any construction lines clearly. [2] (c) Explain, in terms of light rays, if image I is a real image or virtual image. [2] ………………………………………………………………………………........... ………………………………………………………………………………........... 3) Fig. 3.1 shows a cycle pump connected to an airtight glass flask and a pressure gauge. Fig. 3.1 (a) State the change in the reading on the pressure gauge when the piston of the cycle pump was pushed in slowly. [1] ………………………………………………………………………………........... (b) Using the kinetic model of matter, explain how the pressure change in (a) occurred. [3] ………………………………………………………………………………........... ………………………………………………………………………………........... ………………………………………………………………………………........... ………………………………………………………………………………........... ………………………………………………………………………………........... (c) Describe another method to bring about the s ame pressure change in (a) other than pushing in the piston of the cycle pump. [1] ………………………………………………………………………………........... glass flask pressure gauge piston cycle pump

5 4) Fig. 4.1 shows a trapezoidal rough wooden block PQRS. A hand exerted a constant force of magnitude f along PQ on a brick of mass 1.2 kg to slide it continuously at constant speed from P to Q. Subsequently, the brick is moved from Q to R and pushed off the edge of side R so that it dropped vertically to the ground as shown. Fig. 4.1 (a) State a pair of action-reaction forces involving the brick as it moves from P to Q. [1] ………………………………………………………………………………........... (b) Calculate (i) the work done against gravity to move the block from P to Q. [2] (ii) the magnitude of constant fo rce f if work done against friction was 2.4 J as it moved from P to Q. [2] P Q R S hand brick wooden block ground 1.00 m 0.40 m 0.10 m 1.00 m 0.25 m Z

6 (c) When the block was at position Z as shown in Fig. 4.1, its velocity was 2.0 m s-1. (i) If the block was falling freely, calculate the time taken to reach the g round from position Z. [3] (ii) Explain, in terms of forces acting on the block, how the time calculated in (c)(i) would differ if air resistance were present as it fell to the ground. [2] ……………………………………………………………………………..... ……………………………………………………………………………..... 5) Fig. 5.1 shows the displacement -time graph of a particle of a visible light wave of wavelength . colour wavelength / nm violet 380 – 450 blue 450 – 495 green 495 – 570 yellow 570 – 590 orange 590 – 620 red 620 – 750 (a) (i) Calculate the frequency of this wave. [1] displacement time / X 10-15 s 1.0 2.0 3.0 0 Fig. 5.1 Fig. 5.2

7 (ii) Given the speed of light in air is 3.0 X 10 8 m s-1, determine , the wavelength of this wave. [2] (b) A light ray of wavelength  is incident on a glass prism as shown in Fig. 5.3. Fig. 5.3 (i) If the absolute refractive index of the glass prism for this light is 1.47, calculate the critical angle for this light passing from glass into air. [2] (ii) Using your answer from (b)(i), calculate the value of the angle . [2] (iii) Using information from Fig. 5.2, s tate and explain the change in the absolute refractive ind ex of glass if the light ray of wavelength  is replaced by a ray of red light directed along the same path with an angle of incidence of . [3] ……………………………………………………………………………..... ……………………………………………………………………………..... ……………………………………………………………………………..... 30°  nair = 1.00 glass

8 SECTION B (30 Marks) Answer question Q6, Q7 and either Q8A or Q8B in this section 6) In the quest to harness alternative sources of energy, solar energy is o ne of the most popular option. Solar cells or photovoltaic (PV) cells are used to convert light energy from the sun into electrical energy. Currently, the semiconducting materials used in PV cells are either crystalline silicon wafers or thin, good light -absorbing films deposited on coated glass or stainless steel sheets. Image source: http://www.engineering.com/SustainableEngineering/RenewableEnergyEngineering/SolarEnergyEngineering/Photovoltaics/tabid/3 890/Default.aspx Fig. 6.1 Fig. 6.1 shows a PV c