Physical Sciences Grade 11 IEB June 2019 Question Paper

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Downloaded from hlayiso.com GRADE 11 June 2019 PHYSICAL SCIENCES TIME: 2 hours + 10 mins reading time 130 marks PLEASE READ THE FOLLOWING INSTRUCTIONS CAREFULLY. 1. This paper consists of 10 pages, and a Data Sheet. Please make sure that your question paper is complete. 2. Answer ALL the questions. 3. Read the questions carefully. 4. Question 1 consists of 5 multiple-choice questions. There is only one correct answer to each question. The letter that corresponds with your choice of the correct answer must be marked with a cross as shown in the example below: A B C D Here, C is the answer 5. Use the data and formulae whenever necessary. 6. Start each question on a new page. 7. You may use an approved, non-programmable and non-graphical calculator, unless otherwise stated. 8. Units need not be included in the working of calculations, but appropriate units should be shown in the answer. 9. Where appropriate, express answers to TWO decimal places. 10. It is in your own interests to write legibly and set your work out neatly. Page 1 of 10

Downloaded from hlayiso.com QUESTION 1 Answer these questions on the Answer Sheet provided. Make a cross (X) in the box corresponding to the letter that you consider to be correct. 1.1 Newton’s Second Law can be expressed mathematically as Fnet = ma. This equation consists of: A. one vector quantity and two scalar quantities B. two vector quantities and one scalar quantity C. three vector quantities D. three scalar quantities (2) 1.2 A 20,4 kg box remains at rest on a horizontal surface while the box is pushed horizontally with a force of 60 N. The coefficient of static friction between the box and the surface is 0,60. What is the force of friction acting on the box during the push? (Rounded off to the closest whole number) A. 200 N B. 140 N C. 120 N D. 60 N (2) 1.3 The chemical formula for potassium chlorate is: A. K2CℓO3 B. K3CℓO2 C. KCℓ D. KCℓO3 (2) 1.4 The carbon tetrachloride molecule ( CCl4 ) is non-polar because: A. The atoms in the molecule have a linear arrangement. B. The molecule is not symmetric. C. The difference in the electronegativity of the atoms is too small. D. The molecule is tetrahedral. (2) 1.5 8 mole of zinc is mixed with 7 mole of hydrochloric acid and allowed to react to form zinc chloride and hydrogen gas, according to the following balanced equation: Zn(s) + 2 HCℓ(aq) → ZnCℓ2(aq) + H2(g) If 2 mole of H2(g) is formed during the reaction, the number of moles of Zn(s) and HCℓ(aq) that remain in the container respectively are: Mol of Zn Mol of HCl A 6 5 B 0 5 C 0 1 D 6 3 (2) [10] Page 2 of 10

Downloaded from hlayiso.com QUESTION 2 2.1 A toy car is pushed in a northerly direction along the ground for several seconds and then released. The car continues to move until friction brings it to rest. The velocity-time graph shown below represents the motion of the toy car. The total distance travelled by the toy car in 17,5 s is 29,8 m. 2.1.1 Define velocity. (2) 2.1.2 Calculate the magnitude of the maximum velocity of the car. (3) 2.1.3 Calculate the acceleration of the car during the last 14 s (3) The car has a mass of 20 kg. The only forces acting on the car during the last 14 s are weight and friction. 2.1.4 State Newton’s Second Law (2) 2.1.5 Calculate the frictional force on the car during the last 14 s. (4) Page 3 of 10

Downloaded from hlayiso.com 2.2 A 75 kg diver jumps from a diving board with an initial upward velocity of 4 m.s-1. He is in the air for 1,3 s before reaching the water below. (Take up as positive) 2.2.1 Calculate the maximum height, above the board, reached by the diver. (3) 2.2.2 Determine the height of the diving board above the water surface. (3) The diver enters the water with a speed of 8,65 m.s-1 and is brought to a stop in a time of 0,9 s while he travels vertically downwards through the water. He then turns around and returns to the surface. 2.2.3 Calculate the magnitude of the deceleration of the diver while in the water. (3) 2.2.4 Calculate the net force which brings the diver to a stop. (4) 2.2.5 Sketch the velocity-time graph to represent the motion of the diver from the time that he leaves the diving board to when he is brought to a stop under water. On your graph show the following: * label the point of maximum height as H * the point at which the diver enters the water as W * his initial velocity * his velocity as he hits the water * the time he hits the water * the time he is brought to a stop under the water (6) [33] Page 4 of 10

Downloaded from hlayiso.com QUESTION 3 A crate, of mass 240 kg, at rest on an inclined plane is just on the point of sliding. The maximum static frictional force acting on the crate is 1 382 N. 240 kg θ 3.1 Draw a fully-labelled, free-body diagram of all the forces acting on the crate. (3) 3.2 If the angle of the slope is 36 ͦ, calculate the co-efficient of static friction between the crate and the surface of the plane. (4) 3.3 The angle of the inclined plane is adjusted to 0 o (i.e. it is now horizontal). A light inextensible cable is attached to the crate and gradually pulled by a motor until the crate is just on the point of sliding. Motor 240 kg 3.3.1 Will the maximum static frictional force now be GREATER THAN, EQUAL TO or LESS THAN it was on the inclined plane? (1) 3.3.2 Explain your answer, by making reference to one or more relevant formulae. No further calculations are required. (4) [12] Page 5 of 10

Downloaded from hlayiso.com QUESTION 4 4.1 Riaan pushes a roller of mass 200 kg with a force of 480 N over a rough horizontal path. The force makes an angle of 37o with the horizontal. Riaan pushes the roller with a constant acceleration of 0,9 m s-2. 4.1.1 Draw a fully-labelled, free-body diagram of all the forces acting on the roller. Remember to consider the relative magnitudes of the forces in your diagram. (4) 4.1.2 Calculate the magnitude of the kinetic frictional force (Ffk) between the roller and the surface. (5) 4.2 Two scale pans each of mass 0,1 kg are attached to a light inextensible cable which passes over a smooth pulley. A mass of 0,5 kg is placed on one pan and a mass of 0,3 kg is placed on the other pan as shown in the diagram. The system is released from rest. 4.2.1 Consider each side separately and use Newton's second law to write an equation for each side. Use your equations to calculate the magnitude of the acceleration of the system. (5) 4.2.2 State Newton's third law of motion. (2) 4.2.3 Describe the force that is the Newton third law pair to the force that the scale pan exerts on the 0,5 kg mass. (2) [18] Page 6 of 10

Downloaded from hlayiso.com QUESTION 5 An astronaut on a planet wants to determine the acceleration due to gravity. The astronaut has a number of different masses available and determines the weight of each mass. The following measurements were recorded by the astronaut: Mass (kg) Weight (N) 0,1 0,30 0,2 0,79 0,3 1,05 0,5 1,90 0,6 2,18 0,7 2,70 5.1 Distinguish between mass and weight. (2) 5.2 Plot a graph of weight (on the y-axis) vs mass (on the x-axis) on the graph paper provided in the answer sheet. (6) 5.3 Calculate the gradient of the graph. Show the values you used on your graph and include the appropriate unit in your answer. (3) 5.4 Hence, determine the acceleration due to gravity on the planet. (2) Use the table of "g values" below to answer the questions that follow. Planet g (m⋅s–2) Venus 8,87 Mars 3,71 Jupiter 23,12 Pluto 0,58 5.5 Which planet is the astronaut on? (1) 5.6 The radius of Pluto is 1,19 ×106 m. Determine the mass of Pluto. (4) [18] Page 7 of 10

Downloaded from hlayiso.com QUESTION 6 6.1 160 cm3 of a 1,5 mol.dm-3 nitric acid (HNO3) standard solution reacts with 15 g of calcium carbonate, according to the following balanced reaction: 2HNO3 + CaCO3  Ca(NO3)2 + H2O + CO2 6.1.1 Calculate the number of moles of nitric acid used. (3) 6.1.2 Using suitable calculations, determine the limiting reagent in the (4) above reaction. 6.2 The purity of a sample of NaCℓ was tested by means of a reaction represented by the following balanced chemical equation: 10NaCℓ(s) + 8H2SO4+ 2KMnO4 → 5Cℓ2(g) + 2MnSO4 + 5Na2SO4 + K2SO4 + 8H2O When 20 g of impure NaCℓ was treated with excess H2SO4 and KMnO4, 3,36 dm3 of chlorine gas (Cℓ2) was formed at STP. Calculate the % purity of the NaCℓ sample. (8) [15] QUESTION 7 Consider the following substances at room temperature represented by their chemical formulae. Ne (g) CF4(g) NH3(g) HCℓ (g) KBr (s) Zn(s) SiO2(s) Use the substances in the list once, more than once or not at all in response to the descriptions. Give the formula of ONE substance from the above list which …. 7.1 experiences hydrogen bond forces when in the liquid phase. 7.2 conducts electricity when molten but not as a solid. 7.3 has delocalised valence electrons. 7.4 does not dissolve in water but dissolves in CCl4 7.5 has induced dipole (London) forces between its atoms 7.6 has a giant covalent network structure [6] Page 8 of 10

Downloaded from hlayiso.com QUESTION 8 Consider the list of six substances with their formulae and boiling points in the table below: NAME OF FORMULA BOILING POINT MELTING POINT SUBSTANCE (OC) (OC) Water H2O 100 0 Bromine Br2 58,8 -7 Iodine I2 184,3 114 Ammonia NH3 -33,3 -78 Phosphine PH3 -87,7 -133 Sodium chloride NaCl 1074 8.1 Define the following terms: 8.1.1 Intramolecular bond (2) 8.1.2 Intermolecular force (2) 8.2 Consider bromine. 8.2.1 Name the intermolecular force found between bromine molecules. (1) 8.2.2 Provide the specific name for the intramolecular bond found in Br2. (2) 8.3 Explain, why the melting point of iodine is higher than the melting point of bromine . (4) 8.4 Explain why the heat energy required to melt sodium chloride is large by referring to the image below. (3) Source: http://physicsopenlab.org accessed on 11 August 2018 Page 9 of 10

Downloaded from hlayiso.com 8.5 The diagram below shows the arrangement of water particles around a dissolved sodium ion. 8.5.1 What is the name of the intermolecular force responsible for this dissolving process? (1) 8.5.2 Which molecular substance in the table is extremely soluble in water? Explain your choice (3) [18] [Total marks = 130] Page 10 of 10 Powered by TCPDF (www.tcpdf.org)