Name: ________________________ Class: ___________________ Date: __________ Exam 1, PHYS 201, 08F Multiple Choice Identify the choice that best completes the statement or answers the question. ____ ____ 1. Which of these is the standard for the kilogram? a. a fraction of the mass of the Earth c. the mass of 3x108 photons b. the mass of a billion billion Cesium d. the mass of a particular platinum-iridium atoms cylinder 3 2. The volume of a room is 1000 m . What is the volume in cubic centimeters? ____ a. 1x10-3 cm3 d. 1x1012 cm3 b. 10 cm3 e. 1x105 cm3 9 3 c. 1x10 cm 3. In this graph, what is the instantaneous acceleration at point C? a. b. c. 1 m/s2 -1 m/s2 -2 m/s2 d. e. 1 2 m/s2 none of these ID: A Name: ________________________ ____ ____ 4. In the previous graph, what is the average acceleration between points A and C? d. -2 m/s2 a. 0.4 m/s2 2 b. 1 m/s e. Not enough information c. 0.33 m/s2 5. You throw a very bouncy ball toward the ground; it bounces off the ground and returns to your hand at the same speed at which you threw it.. Which of these plots best describes the motion of the ball from the moment you release it to the moment you catch it? a. ____ ID: A c. b. d. 6. You throw a ball upwards with an initial velocity of 20 m/s. How high does the ball go? a. b. 10 m 20 m c. d. 2 60 m 40 m Name: ________________________ ____ 7. This figure shows the vectors A and B. What is the resultant vector of A-B? a. ____ ID: A c. b. d. 8. While exploring a cave a spelunker starts at the entrance and moves the following distances: 30.0 m west, 20.0 m at an angle 40.0° north of east, and 100. m south. What is the magnitude of his resultant displacement? a. b. 150. m 122 m c. d. 3 102 m 88.3 m Name: ________________________ ____ ID: A 9. A guy walks 10 meters towards the North. Then, he walks 5 meters to the east. What is the angle of his displacement? c. 84° Ε of N a. 79° S of Ε d. 63° Ν of Ε b. 27° Ν of Ε ____ 10. Which of these statements about the motion of a projectile is/are true? I. The x-component of the velocity does not change. II. The y-component of the velocity increases throughout the trajectory. III. The x-component of the acceleration is zero. IV. The maximum height is dependent on the x-component of the velocity V. The maximum range is dependent only on the x-component of the velocity. a. b. c. III d. I & III e. I, III, & V ä has components A and A . If || A || > ____ 11. The vector A x x y II & IV All are true | A | (that is, the magnitude of the x-component is greater | y| A? than the magnitude of the y-component), which of these is a possible angle for ä I. 60º above the positive x-axis II. 30º above the positive x-axis III. 40º below the negative x-axis IV. 45º below the positive x-axis a. II, III, & IV d. IV b. I e. II c. II & III ____ 12. A ferris wheel has a radius of 20 m and makes 10 revolutions per minute. What is the magnitude of the centripetal acceleration on a person at the top of the ferris wheel? a. b. 20 m/s2 3x107 m/s2 c. d. 4 200 m/s2 the ferris wheel is turning at a constant speed, so the acceleration is zero Name: ________________________ ID: A ____ 13. The centripetal acceleration of an object points in which direction? a. in the direction of motion c. in the same direction as the velocity b. towards the center of the circular path d. not enough information ____ 14. The following is the function for the position of a particle: x = 3t 2 8i − 5t 3 8j + (3t − 4)k8 What is the magnitude of the acceleration at t=1 second? c. a. 6 m/s2 2 b. 15 m/s d. ____ 15. Which of these is the definition of acceleration? -9 m/s2 30 m/s2 d2x dt 2 dx II. dt dv III. dt speed IV. time I. a. b. c. I IV I & III d. e. 5 II I, III, & IV Name: ________________________ ID: A Problem 16. Derive these equations using methods of differential calculus. v = v 0 + at 1 x = x 0 + v 0 t + 2 at 2 - 6 Name: ________________________ ID: A 17. In this figure, a stone is projected at a cliff of height, h, with an initial speed of 30.0 m/s directed at angle θ0=50° above the horizontal. The stone strikes at A, 2.0 seconds after launching. Find the following: a) The height of the cliff b) the speed of the stone just before impact at A c) the maximum height H above the ground - 7 Name: ________________________ ID: A 18. The position ä x of a particle moving in the xy plane is given by ä x = (2t 3 − 2t 4 )i8 + (t 2 − 3t)j8, with ä x in m and t>0s. a) What is the acceleration, in vector notation, when t=2.0 s? b) What is the magnitude of the acceleration at t=2.0s? c) When (if ever) is the velocity zero? d) What is the x-coordinate when the particle is at its maximum y-coordinate? - 8 ID: A Exam 1, PHYS 201, 08F Answer Section MULTIPLE CHOICE 1. 2. 3. 4. 5. 6. 7. ANS: ANS: ANS: ANS: ANS: ANS: ANS: HW D C C A A B C PTS: PTS: PTS: PTS: PTS: PTS: 1 1 1 1 1 1 PTS: PTS: PTS: PTS: PTS: PTS: PTS: 1 1 1 1 1 1 1 PTS: 1 8. ANS: D HW 9. 10. 11. 12. 13. 14. 15. PTS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: 1 D B C A B D C PROBLEM 16. ANS: Derivation PTS: 1 17. ANS: ?? PTS: 1 18. ANS: ?? PTS: 1 1