SPH 4U Holy Cross Catholic Secondary School PHYSICS 12 (SPH 4U) Final Exam June 2010 Time: 2.5 hrs Teacher: Mr. Pendergast Total Marks: 83 30% of final mark -(24% Sections A-C , 2% Lab problem, 2% extended response, 2% STSE ) Name: ______________________________ Instructions: This exam consists of four parts, which may be completed in any order. Below is a breakdown with a suggested time guide. Part A Multiple Choice 25 marks - 40 min. Part B Short Answers 22 marks - 40 min. Part C Problems 36 marks - 70 min. Total 83 marks - 150 min *A formula sheet has been provided with the exam. *ESL students are allowed to use a dictionary, not a translator *There are no penalties for wrong answers. Do not leave any question blank. *Calculators are permitted but their memories must be erased. *Assume all data is accurate to the number of digits given and round off final answers accordingly. *The use the following constants where appropriate. Mass Moon = 7.35 x 10 22 kg Earth = 5.98 x 10 24 kg electron = 9.11 x 10-31 kg proton = 1.67 x 10 -27 kg neutron = 1.68 x 10 -27 kg sun = 1.99 x 1030 kg Distances Moon’s radius = 1738 km Earth - Sun = 1.5 x 10 11 m Earth’s radius = 6.37 x 10 6 m Earth - moon = 3.82 x 10 8 m Physical Constants Constants G = 6.67 x 10-11 N≅m2/kg2 uair = 4π x 10-7 T≅m/A k = 9.0 x 109 N≅m2/C2 h = 6.626 x 10 -34 J≅s c = 3.00 x 108 m/s 1 u = 1.661 x 10 -27 kg 1 u = 931.5 MeV/c2 Charges electron = -1.6 x 10-19 C proton = 1.6 x 10 -19 C Part A Multiple Choice (25 marks) 1 Final Exam SPH 4U June 2010 Identify the choice that best completes the statement or answers the question. ____ 1. Which factor increases the force of friction acting on an object that is sliding down an incline? a. increasing the surface area in contact b. decreasing the surface area in contact c. lubricating the surfaces in contact d. increasing the angle of the incline plane e. decreasing the angle of the incline plane Yo-yo Diagram A yo-yo is fully extended and is being swung clockwise in a horizontal circle on a frictionless surface. It takes 3.5 s for the yo-yo to complete one revolution. The yo-yo travels a distance of 5.3 m from point A to point C. ____ 2. Use the yo-yo diagram. At the point labelled “D,” what would be the direction of the velocity vector? a. ← d. ↓ b. ↑ e. perpendicular to the object’s motion c. → ____ 3. Use the yo-yo diagram. What would be the direction of the acceleration vector at the point labelled “D”? a. ← d. ↓ b. ↑ e. perpendicular to the object’s motion c. → ____ 4. If the period of a simple harmonic motion is 2.0 s, what is the frequency? a. zero b. 0.5 Hz c. 1.0 Hz d. 1.5 Hz e. 2.0 Hz ____ 5. The name given to an electromagnetic wave (for example, X ray, radio wave) depends on the wave’s a. colour b. speed c. amplitude d. wavelength e. intensity ____ 6. Monochromatic light of wavelength λ is directed through a double slit with width AB. The second dark fringe occurs at P. What is the path difference |BP − AP|? a. 0 b. λ c. 1.5λ d. 2λ e. 2.5λ 2 Final Exam ____ SPH 4U June 2010 7. What is the gravitational force between the two masses in the system described by the data below? System 1 2 Mass 1 (kg) 1 2 Mass 2 (kg) 2 4 Separation distance (m) 2 1 Gravitational force (N) F ? 2 a. F b. 8F c. 16F d. 32F e. 64F ____ 8. A puck hits a wall at 2.0 m/s[E] and rebounds. If the collision is elastic, which of the following will undergo a change? a. speed b. kinetic c. gravitational d. momentum e. mass energy potential energy ____ 9. Which of the following has the greatest momentum? a. a hockey puck flying past a goalie into the net b. a cat running after a mouse c. your school building d. a transport truck moving at 100 km/h on a highway e. the Moon in its orbit around Earth ____ 10. Suppose a cannon is designed in such a way that the cannon ball is heavier than the cannon. Which of the following is a false statement about what happens when the cannon fires? a. The law of conservation of momentum applies. b. The sum of the momenta is zero. c. The cannon recoils at a speed faster than the cannon ball shoots out. d. The law of conservation of momentum does not apply. e. The law of conservation of energy applies. ____ 11. Which field(s) does a moving charged particle generate? a. magnetic field d. magnetic field and electric field b. gravitational field e. electric field and gravitational field c. electric field ____ 12. Which scientist first proposed matter waves? a. Albert Einstein b. Max Planck c. Heinrich Hertz d. Louis de Broglie ____ 13. Which object is an inertial frame of reference? a. a merry-go-round b. a car gaining or losing speed c. a car at rest d. a car rounding a curve at constant speed e. either a car at rest or a car rounding a curve at constant speed ____ 14. As seen by an observer at rest, which quantity of a body is smaller when the body is moving at a relativistic speed than when the body is moving at a non-relativistic speed? a. elapsed time between two on-board d. momentum events b. mass e. kinetic energy c. length 3 Final Exam SPH 4U June 2010 ____ 15. In a completely dark room, what does a body at a temperature of 20°C emit? a. no radiation d. mainly infrared radiation and ultraviolet radiation b. mainly infrared radiation e. depends on the colour of the body c. mainly ultraviolet radiation ____ 16. How can an electron in an atom emit a photon? a. by remaining at its energy level b. by “falling” to a lower energy level c. by “rising” to a higher energy level d. by wave particle duality e. by reduction of its wave function ____ 17. Which element has the greatest binding energy per nucleon? a. carbon b. iron c. hydrogen d. helium e. uranium ____ 18. In a chain reaction involving uranium, which type of particle enters and destabilizes uranium nuclei? a. a proton d. an alpha particle b. a neutron e. a beta particle c. an electron ____ 19. How much of a radioactive substance remains after three half-lives? a. one half b. one third c. one quarter d. one sixth ____ 20. An object can not have a charge of a. 3.2 x 10–19C b. 4.5 x 10–19C c. d. e. one eighth 8.0 x 10–19 C 9.6 x 10–19 C ____ 21. A baseball is thrown vertically into the air. The instantaneous acceleration of the aball at the highest point in its travel is a. 9.8 m/s2 up b. 9.8 m/s2 down c. changing from 9.8 m/s2 down to 9.8 m/s2 up d. changing from 9.8 m/s2 up to 9.8 m/s2 down e. zero ____ 22. You throw a rock straight up into the air. While it falls, its total energy a. remains constant c. decreases then increases b. increases steadily d. increases then decreases 4 Final Exam SPH 4U June 2010 ____ 23. 26. A free electron and a free proton are placed between two oppositely charged parallel plates. Both are closer to the positive plate than the negative plate. See diagram to the right. Which of the following statements is true? I. The force on the proton is greater than the force on the electron. II. The potential energy of the proton is greater than that of the electron. III. The potential energy of the proton and the electron is the same. a. b. c. I only II only III only D d. e. I & II only I & III only ____ 24. Two cars approach each other, each at speed v. The driver of car A turns on its headlights. The driver of car B sees the light (the leading edge of the photons, not the headlight image) approaching. At what speed is the light approaching? a. v b. c c. v + c d. 2v ____ 25. Diffraction refers to a. the bending of a wave around a corner b. the monochromatic nature of light c. the separation of white light into the visible spectrum d. the bending of light when it changes mediums 5 Final Exam SPH 4U June 2010 Part B Short Answer (22 marks) 1. Given the following velocity- time graph, determine i) when the object was stopped (1marks) ii) the acceleration of the object at 6.0 s (1 marks) iii) the displacement from 0-5 s (1 marks) 2. Red light of wavelength 620 nm is shining through a double slit of 1.20 x 10 -4 m. Determine the distance between the first and fourth nodal lines if the screen is 24 m away. (2 marks) 3. Determine the magnetic field strenth of a long coil of length 15 cm which has 400 turns if it draws a 12 A current. (2 marks) 4. What is the energy of an electron in Bohr’s hydrogen atom if it is the 3rd orbital? (2 marks) 5. Radioactive iodine - 128 has a half-life of 25 min, is sometimes used to treat thyroid problems. If 40 mg of iodine 128 is injected into a patient, how much will remain after 100 min. (2marks) 6 Final Exam SPH 4U June 2010 6. A 5.0 kg cart is pulled from rest along a straight line with the horizontal force shown in the graph. Find the kinetic energy of the cart at 4.0 m. (2 marks) 7. List 4 examples of electromagnetic radiation placing them in order from lowest frequency to highest frequency. (2marks) ____________ _____________ _____________ ____________ 8. Write the equation for each reaction. a) carbon-10 (106 C) decayed by positron emission Au) decayed by beta minus emission b) gold-198 (198 79 Ra) decayed by alpha emission c) radium-223 (223 88 (3 marks) 9. An electron is moving at 0.995c, parallel to a metre stick. How long is the metre stick in the electron’s frame of reference? (2 marks) 10. A physics student has a mass of 78 kg. The mass of a physics textbook is 1.4 kg. Determine the force of gravitational attraction between the student and the textbook if there is 1.2 m between their centres. (2 marks) 7 Final Exam SPH 4U June 2010 Part C Problems ( 36 marks) - answer any 6 of the following 7 questions 1. A 2.9 × 10−13 kg latex sphere (balloon) is moving up, at a constant velocity of 0.013 mm/s, between two large horizontally plates. The plates are 1.500 cm apart, with a potential difference of 3.00 × 102 V between them. How many extra electrons does the sphere have? (6 marks) 2. Three charges sit on the vertices of triangle with side lengths of 5 cm, 5 cm and 10 cm. The interior angles of the triangle are 25o, 25o, 130o. If charge A is 6 uC, charge B is 7 uC, and charge C is 9 uC, a) determine the force exerted on charge C by charge A. ( 2 marks) b) determine the net force on charge A. (4 marks) 3. The work function of a particular metal is 3.2 eV. If a photon of wavelength 270 nm hits the plate then a) what is the energy of the emitted electron? (4 marks) b) what is the velocity of this electron? (2 marks) 4. A 420 kg satellite is launched into a circular orbit and attains an orbital altitude of 950 km above the Earth’s surface. (6 marks) a) Determine the satellite’s orbital velocity. b) Determine the satellite’s total energy. 5. If the collision of the cars is ellastic, determine their velocities after the collision. (6 marks) 6. A projectile is 2.6 m above the ground and is launched with a horizontal velocity of 12 m/s. How far horizontally does the projectile travel? (6 marks) 7. Eric and Josh decide to retry the friction lab. This time, their procedure will consist of letting an object slide up an incline plane and they will measure the distant travelled until the objects stops, assuming that the frictional force is constant during its entire trip up the plane. Their data consists of a 2.0 kg wooden block with an iniatial velocity of 3 m/s sliding up an incline plane, inclined at 30 o to the horizontal, a distance of 47 cm. Determine the object’s coefficient of friction. Include a freebody diagram. (6 marks) 8 Final Exam SPH 4U June 2010 Part D Lab Question (12 marks) 1. The following data was collected from our conservation of momentum in two dimensions lab. Observations (scale 1cm = 6cm) Questions 1. Construct a table of the results indicating an appropriate uncertainty. (4 marks) 2. Mathematically, analyze the data to determine if momentum was conserved. (4 marks) 9 Final Exam SPH 4U June 2010 3. Discuss the precision and accuracy of your results. (4 marks) 10 ID: A SPH 4U Answer Section MULTIPLE CHOICE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: E B C B D D E D E D D D C C B B B B E B B A B B A PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: DIF: difficult easy average easy easy easy difficult average easy difficult easy easy easy average easy average easy easy average DIF: easy SHORT ANSWER 1. ANS: d PTS: 1 2. ANS: f PTS: 1 3. ANS: f PTS: 1 1 REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: REF: K/U K/U K/U K/U K/U K/U K/U K/U K/U K/U K/U K/U MC K/U K/U K/U K/U K/U MC REF: K/U ID: A 4. ANS: d PTS: 1 5. ANS: f PTS: 1 6. ANS: f PTS: 1 7. ANS: d PTS: 1 8. ANS: a) 106 C → −10 e + 105 B b) c) 198 79 223 88 Au → −10 e + 198 Hg 80 Ra → 42 He + 219 Rn 86 PTS: 1 9. ANS: L0 L= DIF: average REF: K/U γ 100 cm = 10.0 = 10 cm PTS: 1 DIF: easy REF: K/U 10. ANS: m1 m2 Fg = G 2 r ÁÊÁ N • m2 ˜ˆ˜˜ (78 kg)(1.4 kg) ˜ = ÁÁÁÁ 6.67 × 10 −11 2 kg2 ˜˜˜ ÁË (1.2 m) ¯ = 5.06 × 10−9 N PTS: 1 DIF: easy REF: K/U 2 ID: A PROBLEM 1. ANS: FQ = Fg ä E q = mg Q q= mg ä E Q mg ΔV Δd (2.90 × 10−13 kg)(9.81 N/kg) = ÁÊÁ 3.00 × 10 2 V ˜ˆ˜ ÁÁ ˜ ÁÁ 1.50 × 10 −2 m ˜˜˜ Á ˜ Ë ¯ −16 = 1.42 × 10 N • m/V = 1.42 × 10−16 C 1.42 × 10 −16 C e number = 1.602 × 10 −19 C/electron = 8.88 × 10 2 electrons q= PTS: 1 2. ANS: v DIF: average REF: K/U PTS: 1 3. ANS: v PTS: 1 4. ANS: none PTS: 1 5. ANS: v PTS: 1 3 ID: A 6. ANS: Consider the vertical components of the projectile. vvi = 0, ag = 9.81 m/s2, dv = 2.6 m, t = ? 1 dv = vvit + at2 2 2d t2 = ag 2 (2.6 m) 9.81 m/s 2 = 0.53 t = 0.73 s Consider the horizontal components of the projectile. t = 0.73 s, vh = 12 m/s, dh = ? dh = vh(t) = (12 m/s)(0.73 s) = 8.8 m = PTS: 1 7. ANS: c DIF: average REF: K/U PTS: 1 OTHER 1. ANS: k PTS: 1 4