paper 2 2000

paper 2 2000 - N00/430/S(2) INTERNATIONAL BACCALAUREATE...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: N00/430/S(2) INTERNATIONAL BACCALAUREATE BACCALAURÉAT INTERNATIONAL BACHILLERATO INTERNACIONAL Name PHYSICS STANDARD LEVEL PAPER 2 Number Friday 10 November 2000 (afternoon) 1 hour INSTRUCTIONS TO CANDIDATES ! ! ! ! ! Write your candidate name and number in the boxes above. Do not open this examination paper until instructed to do so. Section A: Answer all of Section A in the spaces provided. Section B: Answer one question from Section B in the spaces provided. At the end of the examination, indicate the number of the Section B question answered in the box below. QUESTIONS ANSWERED EXAMINER SECTION A ALL SECTION B ......... TEAM LEADER /25 /25 /25 /25 /25 /25 TOTAL TOTAL /50 880-236 IBCA TOTAL /50 /50 20 pages –2– Blank page 880-236 N00/430/S(2) –3– N00/430/S(2) SECTION A Candidates must answer all questions in the spaces provided. A1. Planetary orbits: graphical analysis The figure below shows the orbits of the four innermost planets around the Sun, with the orbit of Jupiter further out. Sun Mercury Venus Jupiter Earth Mars Orbits of the four innermost planets (not to scale) Orbit of Jupiter Kepler worked for many years to find a relation between the motions of the planets, examining possible combinations of factors that might be involved. Finally in 1619 he published his third law, stating that the squares of the orbital periods T are proportional to the cubes of the mean distances R from the Sun. That is, T 2 = kR 3 , where k is a constant. To check if this relationship is valid we can plot T 2 versus R 3 . Data for the four innermost planets is plotted opposite. (This question continues on the following page) 880-236 Turn over –4– N00/430/S(2) (Question A1 continued) 4 • T 2 / years 2 Mars 3 2 1 • Earth • Venus 0 • Mercury 0 20 40 60 R /1032 m3 80 100 120 3 (a) Do the plotted points indicate that the motions of the innermost planets are consistent with the relationship proposed by Kepler? Explain. [1] ......................................................................... ......................................................................... (b) From your graph, determine the value of the constant k in Kepler’s relationship. Include the units. [2] ......................................................................... ......................................................................... ......................................................................... ......................................................................... (c) Jupiter, the first of the outermost planets, has an observed period of very nearly 12 years. Determine its mean distance from the Sun. ......................................................................... ......................................................................... ......................................................................... ......................................................................... 880-236 [3] –5– N00/430/S(2) A2. Hoisting a container A container of mass 2000 kg is hoisted by an electrically operated crane as shown in Figure 1, in order to be loaded onto a ship. Initially the container is accelerated upwards briefly, after which it is hoisted at a constant speed. Physical system Free-body diagram • Free-body diagram • • Accelerating upwards Figure 1 (a) Figure 2 Moving upwards at constant speed Figure 3 On Figures 2 and 3 above, draw free-body force diagrams showing and labelling the forces acting on the container during the acceleration and constant velocity stages. Use longer vectors for greater forces. State what object exerts each force. [3] ......................................................................... (b) The safety limit for the tension in the cable is 25000 N. Determine the maximum permissible upward acceleration of the container if the limit is not to be exceeded. [2] ......................................................................... ......................................................................... (c) After the initial acceleration, the crane continues hoisting the container at a constant upward speed of 0.5 m s −1 . (i) Calculate the power output of the crane during this stage. [2] ..................................................................... ..................................................................... (ii) The crane’s electric motor operates at 400 V. Assuming no power losses, calculate the current drawn by the motor during hoisting. [2] ..................................................................... ..................................................................... (iii) Eventually the container reaches a height sufficient for loading onto the ship. What has become of the electrical energy supplied to the motor? [1] ..................................................................... 880-236 Turn over –6– N00/430/S(2) A3. Electric circuit This question involves physical reasoning and calculations for electric circuits. Light bulbs are marked with the rating 10 V; 3 W. Suppose you connect three of the bulbs in series with a switch and a 30 V battery as shown in Figure 1 below. Switch S is initially open. S 30 V A B C Figure 1 (a) A student tells you that after switch S is closed, bulb C will light up first, because electrons from the negative terminal of the battery will reach it first, and then go on to light bulbs B and A in succession. Is this prediction and reasoning correct? How would you reply? [2] ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... (b) State how the brightnesses of the three bulbs in the circuit will compare with each other. [1] ......................................................................... ......................................................................... (This question continues on the following page) 880-236 –7– N00/430/S(2) (Question A3 continued) (c) The student now connects a fourth bulb D across bulb B as shown in Figure 2 below. S 30 V A B C D Figure 2 When she connects D, what will happen to the brightnesses of bulbs A, B and C? Explain your reasoning. [3] ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... (d) Assuming that the resistance of the bulbs remains constant, calculate the power output of bulb B in the modified circuit in Figure 2. [3] ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... 880-236 Turn over –8– N00/430/S(2) SECTION B This section consists of three questions: B1, B2 and B3. Answer one question in this section. B1. This question is in two parts. Part 1 is about a collision and Part 2 is about beats. Answer both parts if you choose B1. Part 1. Collision between car and truck A car and a truck are both travelling at the speed limit of 60 km h −1 but in opposite directions as shown. The truck has twice the mass of the car. The vehicles collide head-on and become entangled together. (a) During the collision, how does the force exerted by the car on the truck compare with the force exerted by the truck on the car? Explain. [2] ......................................................................... ......................................................................... ......................................................................... (b) In what direction will the entangled vehicles move after collision or will they be stationary? Support your answer, referring to a physics principle. [2] ......................................................................... ......................................................................... ......................................................................... (c) Determine the speed (in km h −1 ) of the combined wreck immediately after the collision. [3] ......................................................................... ......................................................................... ......................................................................... ......................................................................... (This question continues on the following page) 880-236 –9– N00/430/S(2) (Question B1 Part 1 continued) (d) How does the acceleration of the car compare with the acceleration of the truck during the collision? Explain. [2] ......................................................................... ......................................................................... ......................................................................... (e) Both the car and truck drivers are wearing seat belts. Which driver is likely to be the more severely jolted in the collision? Explain. [2] ......................................................................... ......................................................................... ......................................................................... (f) The total kinetic energy of the system decreases as a result of the collision. Is the principle of conservation of energy violated? Explain. [1] ......................................................................... ......................................................................... (This question continues on the following page) 880-236 Turn over – 10 – N00/430/S(2) (Question B1 continued) Part 2. Beats This question is about the formation of beats in sound waves. (a) State the principle of linear superposition as applied to waves. [2] ......................................................................... ......................................................................... ......................................................................... Two tuning forks A and B of slightly different frequencies are sounded simultaneously, producing two sound waves of the same amplitude. The figure below shows the disturbance at a particular point in the air as a function of time for each of the tuning forks separately, and the resultant disturbance C. A 1 0 B −1 1 0 −1 2 P 1 0 C −1 −2 (b) R Q 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 t / ms Three points on the resultant waveform are labelled P, Q and R. For each of these points, check whether the resultant waveform C as drawn is approximately correct, by referring to the two component waves. Explain in each case. [3] Point P: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Point Q: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Point R: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (This question continues on the following page) 880-236 – 11 – N00/430/S(2) (Question B1 Part 2 continued) (c) Use the diagram to determine (i) [2] the frequencies of A and B; A: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (ii) the beat frequency. [2] ..................................................................... ..................................................................... ..................................................................... (d) (i) Beats at this frequency could not actually be perceived as beats by human hearing. Explain why. [1] ..................................................................... ..................................................................... (ii) In order that the beats become perceived as such by the ear, would the difference in frequency between A and B have to be greater or smaller than in the case above? [1] ..................................................................... ..................................................................... (e) Explain how use could be made of beats to tune a guitar string against a tuning fork. [2] ......................................................................... ......................................................................... ......................................................................... ......................................................................... 880-236 Turn over – 12 – N00/430/S(2) B2. This question is in two parts. Part 1 is about a stone projected upwards and Part 2 is about Rutherford scattering. Answer both parts if you choose B2. Part 1. Stone projected upwards from a cliff A stone is projected almost vertically upwards at 20 m s −1 from the edge of a cliff as shown. It finally lands on the ground at the base of the cliff. The sequence diagram below shows the position of the stone at one-second intervals. Image 0 is just after projection, and Image 5 is just before landing. Gravitational acceleration is taken as 10 m s −2 and air resistance is ignored. 2 t=2s t =1 s 1 3 t =3s 4 t=4s 5 t =5 s 20 m s −1 0 (This question continues on the following page) 880-236 – 13 – N00/430/S(2) (Question B2 Part 1 continued) (a) State whether the stone’s acceleration is upward, downward or zero in each of the following cases: (i) when the stone is on its way up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (ii) when the stone is on its way down ........................................ (iii) when the stone is at the top of its path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (b) (c) [3] Next to each of the six images draw in a vector to represent the instantaneous velocity at that stage of the motion. The vector at image 0 has been drawn in for you. Pay attention to the direction and relative lengths of the vectors, and label them with their magnitudes in m s −1 . [3] Draw a velocity–time graph to represent the motion of the stone. On the graph label the stages representing upwards motion and downwards motion, and label the topmost point of the motion. [3] 30 20 10 v / m s −1 0 1 2 3 4 5 6 t/s −10 −20 −30 (d) What does the gradient of the graph represent? [1] ......................................................................... (e) Determine the height of the cliff. [3] ......................................................................... ......................................................................... ......................................................................... ......................................................................... (This question continues on the following page) 880-236 Turn over – 14 – N00/430/S(2) (Question B2 continued) Part 2. Rutherford scattering and a nuclear reaction In 1911 Geiger and Marsden bombarded a thin gold foil with alpha particles from a radioactive source. Radioactive source Gold foil Alpha Alpha particles particles (a) Based on ideas about atoms at the time, physicists had expected that the alpha particles would go through the atoms in the foil with very little deflection. They were astonished that some alpha particles were scattered almost completely backward. What did Rutherford conclude from this about the structure of the atom? Explain. [2] ......................................................................... ......................................................................... ......................................................................... ......................................................................... The diagram below shows four alpha particles approaching a gold nucleus. The deflected path of one of them (α 2 ) is shown. Assume that any recoil of the gold nucleus can be neglected. Alpha particles α4 α3 α2 Gold nucleus k l α1 m (b) Draw in the force(s) acting on alpha particle α 2 when it is at the positions labelled k, l and m. Your force vectors should be of the right relative lengths, given that points k and m are twice as far from the nucleus as l is. State the source of any forces you show. [2] ......................................................................... (This question continues on the following page) 880-236 – 15 – N00/430/S(2) (Question B2 Part 2 continued) (c) As α 2 travels the path shown, describe what happens to its electric potential energy, kinetic energy and total energy. The recoil energy of the gold nucleus is negligible. [2] ......................................................................... ......................................................................... ......................................................................... (d) On the diagram, sketch the approximate paths of the three other alpha particles labelled α1 , α3 and α 4 . Explain the paths you have drawn. [4] ......................................................................... ......................................................................... ......................................................................... ......................................................................... (e) For target nuclei of lower atomic number, alpha particles may reach the nucleus and a nuclear reaction may occur. Thus when alpha particles bombard the light element beryllium, neutrons are produced. Complete the equation for the reaction of beryllium with an alpha particle. Include all the atomic and mass numbers. 9 4 880-236 Be + [2] He = n + Turn over – 16 – N00/430/S(2) B3. This question is in three parts. Part 1 is about mixing ice and water, Part 2 is about charging processes and Part 3 is about electromagnetic induction. Answer all three parts if you choose B3. Part 1. Mixing ice and water 2 kg of ice from a freezer at −15 ! C is mixed with 10 kg of water at 30 ! C . (a) Determine the final temperature of the mixture after equilibrium is reached. Energy losses to the environment are negligible. [4] Data: Specific heat capacity of ice: Specific heat capacity of water: 2.1× 103 J kg −1 ! C−1 4.2 × 103 J kg −1 ! C−1 Specific latent heat of melting of ice: 3.4 × 105 J kg −1 ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... ......................................................................... (b) In the stage of the process while the ice is melting, it absorbs energy but its temperature does not increase. Explain, from the molecular point of view, how this can be consistent with the principle of conservation of energy. State what becomes of the energy absorbed. [3] ......................................................................... ......................................................................... ......................................................................... ......................................................................... (This question continues on the following page) 880-236 – 17 – N00/430/S(2) (Question B3 continued) Part 2. Charging processes This question is about two electrostatic charging processes. (a) A rubber rod R is originally uncharged. When rubbed with fur, the rod becomes positively charged. Explain briefly how the net positive charge arises on the rod. [1] ......................................................................... ......................................................................... (b) We now wish to use the positively charged rubber rod to charge a metal rod by electrostatic induction. The diagrams below show the steps in the process. For each step, state what happens and draw the charge distribution in the metal rod. [4] Metal rod (i) The charged rubber rod is brought close to the + + metal rod. + + .................................... .................................... (ii) The metal rod is connected to earth. ++ + .................................... + .................................... Earth (iii) The earth connection is removed. .................................... + + + + .................................... (iv) The rubber rod is removed. .................................... .................................... (This question continues on the following page) 880-236 Turn over – 18 – N00/430/S(2) (Question B3 Part 2 continued) (c) The charged rubber rod can continue to be used to charge additional metal rods by induction. How is this consistent with the principle of charge conservation? Explain, accounting for all charge before and after the process. [2] ......................................................................... ......................................................................... ......................................................................... (This question continues on the following page) 880-236 – 19 – N00/430/S(2) (Question B3 continued) Part 3. Electromagnetic induction A jet aeroplane is flying with velocity v at right angles to the Earth’s magnetic field B near the North pole of the Earth, as shown in the plan view below. The plane’s wingspan (distance between wingtips) is L. The wingtips are labelled P (port) and S (starboard). X X X X X X X X X X X X v X X X X X X X X X X X X LX wing X X X X X X X X X X X X X X X X X X X X X X X X X X X X P e" B X X X X X S X (a) X X X X Consider an electron of charge magnitude e in the metal wing of the plane at the point shown by a dot in the figure. (i) (ii) In what direction will this electron experience a magnetic force due to its motion in the magnetic field? Draw a vector on the diagram to represent the force. [1] State an expression for the magnitude of the force on the electron in this situation. [1] ..................................................................... (This question continues on the following page) 880-236 Turn over – 20 – N00/430/S(2) (Question B3 Part 3 continued) (b) While the plane is flying steadily in the magnetic field, the electrons in the wing experience this magnetic force but do not move along the wing; such motion is opposed by an electric field arising in the wing. (i) Explain how this electric field originates, and draw a vector in the diagram to show its direction. [2] ..................................................................... ..................................................................... ..................................................................... (ii) Explain why the electric force on the electron is exactly equal to the magnetic force, in this situation. (Hint: imagine this were not the case and consider what would happen next.) [2] ..................................................................... ..................................................................... ..................................................................... (c) Show that the magnitude of the electric field produced in the wing is given by E = vB . [1] ......................................................................... ......................................................................... (d) Calculate the magnitude of the electric field when the plane flies at 200 m s −1 (720 km hr −1 ) in the Earth’s field of 8 × 10−5 T near the pole. [1] ......................................................................... ......................................................................... (e) Would the effect still arise if the plane were flying near the Equator? Explain. [1] ......................................................................... ......................................................................... (f) Will there also be a potential difference between the nose and the tail of the plane? Explain why or why not. ......................................................................... ......................................................................... 880-236 [2] ...
View Full Document

Ask a homework question - tutors are online