Faculty of Applied Sciences PHY406 NAME: _________________________________ Semester July – Nov 2010 Phy406-TEST 1 HP #:_________________ SECTION A (Answer ALL QUESTIONS) –Time: 1 hour CIRCLE YOUR BEST CHOICE FOR EACH OF THE QUESTIONS BELOW OR WRITE THE ANSWER NEXT TO THE QUESTION # 1. The mass of a raindrop is 4 milligrams. Which one of the following statements indicates the correct mass of the raindrop in grams? A The raindrop has a mass of 4 x 106 grams. B The raindrop has a mass of 4 x 103 grams. C The raindrop has a mass of 4 x 101 grams. D The raindrop has a mass of 4 x 103 grams. E The raindrop has a mass of 4 x 106 grams. 2. Which one of the following is the longest length? A 100 meters C 104 millimeters 2 B 10 centimeters D 105 micrometers 3. Complete the following statement: The ratio A B 4. 102. 103. C D E 107 nanometers E 106. E 8.0 x 103 cm2 1 milligram is equal to 1 kilogram 106. 103. Which one of the following choices is equivalent to 8.0 m 2? A 8.0 x 10–4 cm2 C 8.0 x 10–2 cm2 2 2 B 8.0 x 10 cm D 8.0 x 104 cm2 5. A certain physical quantity, R, is calculated using the formula: R = 4a2(b – c) where a, b, and c are distances. What is the SI unit for R? A cm C m E m3 2 2 B cm D m 6. Which one of the following quantities is a vector quantity? A the age of the earth B the mass of a freight train C the earth's pull on your body D the temperature of hot cup of coffee E the number of people attending a soccer game 7. Which one of the following statements is TRUE concerning scalar quantities? A Scalar quantities must be represented by base units. B Scalar quantities have both magnitude and direction. C Scalar quantities can be added to vector quantities using rules of trigonometry. D Scalar quantities can be added to other scalar quantities using rules of trigonometry. E Scalar quantities can be added to other scalar quantities using rules of ordinary addition. 8. Two vectors A and B are added together to form a vector C. The relationship between the magnitudes of the vectors is given by: A2 + B2 = C2. Which statement concerning these vectors is TRUE? A A and B must be at right angles to each other. B) A and B could have any orientation relative to each other. C A and B must have equal lengths. D A and B must be parallel. E) A and B could be antiparallel. Tuesday, February 09, 2016 1:08 AM Assoc. Prof. Dr JJ; http://drjj.uitm.edu.my; HP: +60193551621 P a g e |1 Faculty of Applied Sciences 9. PHY406 Semester July – Nov 2010 Three vectors A, B, and C add together to yield zero: A + B + C = 0. The vectors A and C point in opposite directions and their magnitudes are related by the expression: A = 2C. Which one of the following conclusions is correct? A A and B have equal magnitudes and point in opposite directions. B B and C have equal magnitudes and point in the same direction. C B and C have equal magnitudes and point in opposite directions. D A and B point in the same direction, but A has twice the magnitude of B. E B and C point in the same direction, but C has twice the magnitude of B. 10. A displacement vector has a magnitude of 810 meters and points at an angle of 18° above the positive x axis. What are the x and y scalar components of this vector? x scalar component y scalar component A 770 meters 250 meters B 560 meters 585 meters C 585 meters 560 meters D 250 meters 750 meters E 713 meters 385 meters 11. Which one of the following statements concerning vectors and scalars is FALSE? A In calculations, the vector components of a vector may be used in place of the vector itself. B It is possible to use vector components that are not perpendicular. C A scalar component may be either positive or negative. D A vector that is zero may have components other than zero. E Two vectors are equal only if they have the same magnitude and direction. Questions 12-14 refer to a coin which is tossed straight up into the air. After it is released it moves upward, reaches its highest point and falls back down again. Use one of the following choices (A through G) to indicate the force acting on the coin for each of the cases described below. Answer choice J if you think that none is correct. Ignore any effects of air resistance. A. B. C. D. E. F. G. ___ ___ ___ The force is down and constant. The force is down and increasing The force is down and decreasing The force is zero. The force is up and constant. The force is up and increasing The force is up and decreasing 12. 13. 14. The coin is moving upward after it is released. The coin is at its highest point. The coin is moving downward. Questions 15-17 refer to a coin that is tossed straight up into the air. After it is released it moves upward, reaches its highest point and falls back down again. Use one of the following choices (A through G) to indicate the acceleration of the coin during each of the stages of the coin's motion described below. Take up to be the positive direction. Answer choice J if you think that none is correct. A. B. C. D. E. F. G. ___ ___ The acceleration is in the negative direction and constant. The acceleration is in the negative direction and increasing The acceleration is in the negative direction and decreasing The acceleration is zero. The acceleration is in the positive direction and constant. The acceleration is in the positive direction and increasing The acceleration is in the positive direction and decreasing 15. 16. The coin is moving upward after it is released. The coin is at its highest point. Tuesday, February 09, 2016 1:08 AM Assoc. Prof. Dr JJ; http://drjj.uitm.edu.my; HP: +60193551621 P a g e |2 Faculty of Applied Sciences ___ 17. PHY406 Semester July – Nov 2010 The coin is moving downward. Questions 18-21 refer to a toy car which can move to the right or left on a horizontal surface along a straight line (the + distance axis). The positive direction is to the right. 0 Different motions of the car are described below. Choose the letter (A to G) of the velocity-time graph which corresponds to the motion of the car described in each statement. You may use a choice more than once or not at all. If you think that none is correct, answer choice J. ___ 18. Which velocity graph shows the car moving toward the right (away from the origin) at a steady (constant) velocity? ___ 19. Which velocity graph shows the car reversing direction? ___ 20. Which velocity graph shows the car moving toward the left (toward the origin) at a steady (constant) velocity? ___ 21. Which velocity graph shows the car increasing its speed at a steady (constant) rate? Tuesday, February 09, 2016 1:08 AM Assoc. Prof. Dr JJ; http://drjj.uitm.edu.my; HP: +60193551621 P a g e |3 Faculty of Applied Sciences PHY406 Semester July – Nov 2010 Questions 22-26 refer to a toy car which can move to the right or left on a horizontal surface along a straight line (the + distance axis). The positive direction is to the right. 0 Different motions of the car are described below. Choose the letter (A to G) of the acceleration-time graph which corresponds to the motion of the car described in each statement. You may use a choice more than once or not at all. If you think that none is correct, answer choice J. ___ ___ ___ ___ ___ 22. 23. 24. 25. 26. The car moves toward the right (away from the origin), speeding up at a steady rate. The car moves toward the right, slowing down at a steady rate. The car moves toward the left (toward the origin) at a constant velocity. The car moves toward the left, speeding up at a steady rate. The car moves toward the right at a constant velocity. Tuesday, February 09, 2016 1:08 AM Assoc. Prof. Dr JJ; http://drjj.uitm.edu.my; HP: +60193551621 P a g e |4 Faculty of Applied Sciences PHY406 Semester July – Nov 2010 A sled on ice moves in the ways described in questions 27-33 below. Friction is so small that it can be ignored. A person wearing spiked shoes standing on the ice can apply a force to the sled and push it along the ice. Choose the one force (A through G) which would keep the sled moving as described in each statement below. You may use a choice more than once or not at all but choose only one answer for each blank. If you think that none is correct, answer choice J. A. The force is toward the right and is increasing in strength (magnitude). B. The force is toward the right and is of constant strength (magnitude). C. The force is toward the right and is decreasing in strength (magnitude). D. No applied force is needed. E. The force is toward the left and is decreasing in strength (magnitude). F. The force is toward the left and is of constant strength (magnitude). The force is toward the left and is increasing in strength (magnitude). G. __ 27. __ __ 28. 29. __ 30. __ 31. __ 32. __ 33. Which force would keep the sled moving toward the right and speeding up at a steady rate (constant acceleration)? Which force would keep the sled moving toward the right at a steady (constant) velocity? The sled is moving toward the right. Which force would slow it down at a steady rate (constant acceleration)? Which force would keep the sled moving toward the left and speeding up at a steady rate (constant acceleration)? The sled was started from rest and pushed until it reached a steady (constant) velocity toward the right. Which force would keep the sled moving at this velocity? The sled is slowing down at a steady rate and has an acceleration to the right. Which force would account for this motion? The sled is moving toward the left. Which force would slow it down at a steady rate (constant acceleration)? Tuesday, February 09, 2016 1:08 AM Assoc. Prof. Dr JJ; http://drjj.uitm.edu.my; HP: +60193551621 P a g e |5 Faculty of Applied Sciences PHY406 Semester July – Nov 2010 Questions 34-41 refer to a toy car which can move to the right or left along a horizontal line (the positive part of the distance axis). 0 Assume that friction is so small that it can be ignored. You may use a choice more than once or not at all. If you think that none is correct, answer choice . J A force is applied to the car. Choose ONLY one of the force graphs (A through H) for each statement below which could allow the described motion of the car to continue. ___ ___ ___ ___ ___ ___ ___ ___ 34. The car moves toward the right (away from the origin) with a steady (constant) velocity. 35. The car is at rest. 36. The car moves toward the right and is speeding up at a steady rate (constant acceleration). 37. The car moves toward the left (toward the origin) with a steady (constant) velocity. 38. The car moves toward the right and is slowing down at a steady rate (constant acceleration). 39. The car moves toward the left and is speeding up at a steady rate (constant acceleration). 40. The car moves toward the right, speeds up and then slows down. 41. The car was pushed toward the right and then released. Which graph describes the force after the car is released. Tuesday, February 09, 2016 1:08 AM Assoc. Prof. Dr JJ; http://drjj.uitm.edu.my; HP: +60193551621 P a g e |6 Faculty of Applied Sciences PHY406 Semester July – Nov 2010 Section B – Time: 1 hour Questions 1-3 refer to the pictures below which represent the motion of a car moving to the right. The snapshots were taken at intervals of 1 seconds. Car 1 Car 2 Car 3 1. Descibe the physical event represented by each of the picture. 2. Draw a velocity-time graph represented by each picture. (You can draw all three events on the same graph). 3. Draw a position-time graph represented by each picture. (You can draw all three events on the same graph). 4. Suppose you are in an elevator that is moving upward with a constant velocity. A weighing scale inside the elevator shows your weight is 600 newtons (assume the gravitational acceleration is 10 m/s2). For the each of the cases below, discuss (this includes describing the forces, drawing the force diagrams and determining any necessary values) the situation in terms of Newton’s Laws of Motions. (a) The elevator slows down as it comes to a stop. (b) The elevator stops. (c) The elevator picks up speed again on its way back down. Tuesday, February 09, 2016 1:08 AM Assoc. Prof. Dr JJ; http://drjj.uitm.edu.my; HP: +60193551621 P a g e |7