AP Physics Name_______________________ Mrs. Tsarevsky Motion in One Dimension Quiz 1-1 Extra credit: Write the formulas related to this unit. (0.5 for each correct formula) 1. For which one of the following situations will the path length equal the magnitude of the displacement? a) A jogger is running around a circular path. b) A ball is rolling down an inclined plane. c) A train travels 5 miles east; and then, it stops and travels 2 miles west. d) A ball rises and falls after being thrown straight up from the earth's surface. e) A ball on the end of a string is moving in a vertical circle. 2. The velocity of a car is 72 km/h. This velocity in SI units is (a) 20 m/s (d) 2 m/s (b) 200 cm/s (e) 20 cm/s (c) 200 cm/s 3. Which one of the following is an SI base unit? a) gram b) slug c) Newton d) Centimeter e) kilogram 4. A car travels in a straight line covering a total distance of 90.0 miles in 60.0 minutes. Which one of the following statements concerning this situation is necessarily true? (a) The velocity of the car is constant. (b) The acceleration of the car must be non-zero. (c) The first 45 miles must have been covered in 30.0 minutes. (d) The speed of the car must be 90.0 miles per hour throughout the entire trip. (e) The average velocity of the car is 90.0 miles per hour in the direction of motion. 1 AP Physics Name_______________________ Mrs. Tsarevsky 5. A bus leaves New York City, takes a non-direct route and arrives in St. Louis, Missouri 24 hours later. If the distance between the two cities is 1200 km, what is the magnitude of the bus’ average velocity? (a) 20 km/h (c) 46.0 km/h (e) 60 km/h (b) 40 km/h (d) 50 km/h 6. A train approaches a small town with a constant velocity of +30.0 m/s. The operator applies the brake, reducing the train’s velocity to +10.0 m/s. If the average acceleration of the train during braking is –2.00 m/s2, for what elapsed time does the operator apply the brake? (a) 5.00 s (c) 15.0 s (e) 25.0 s (b) 10.0 s (d) 20.0 s 7. A truck accelerates from rest at point A with constant acceleration of magnitude a and subsequently passes points B and C as shown in the figure. a x A B C The distance between points B and C is x, and the time required for the truck to travel from B to C is t. Which expression determines the average speed of the truck between the points B and C? (a) v2 = 2ax (c) v = xt (e) v = at (b) v 8. x t (d) v 1 at 2 2 A cheetah is walking at a speed of 4.00 m/s when it observes a gazelle 12.0 m directly ahead. If the cheetah accelerates at 2 m/s2, how long does it take the cheetah to reach the gazelle if the gazelle doesn’t move? (a) 1.00 s (c) 3.00 s (e) 5.00 s (b) 2.00 s (d) 4.00 s Questions 9 through 11 pertain to the situation described below: An object starts from rest and accelerates uniformly in a straight line in the positive x direction. After 11 seconds, its speed is 70.0 m/s. 9. 10. Determine the acceleration of the object. (a) +3.5 m/s2 (c) –3.5 m/s2 (b) +6.4 m/s2 (d) 6.4 m/s2 (e) +7.7 m/s2 How far does the object travel during the first 11 seconds? 2 AP Physics Name_______________________ Mrs. Tsarevsky 11. (a) 35 m (c) 390 m (e) 770 m (b) 77 m (d) 590 m What is the average velocity of the object during the first 11 seconds? (a) +3.6 m/s (c) +35 m/s (e) 140 m/s (b) +6.4 m/s (d) +72 m/s An object is at x = –3 m and has a velocity of 4 m/s. It is observed to be slowing down. Its acceleration is (a) positive. (b) negative. (c) zero. (d) negative until the object stops and then positive. (e) impossible to determine based on the information provided. 13. The graph shows the height versus time of an object. Estimate the instantaneous velocity, in m/s, of the object at time t = 15 sec. (a) 42 m/s 80 (b) 36 m/s (c) 24 m/s 60 (d) 12 m/s (e) 6 m/s 40 Height (meters) 12. 20 0 14. 20. 0 10 20 30 Time (seconds) 40 An object, located at the origin when t = 0, moves along the x axis as shown in the diagram. At which point is the object farthest from its starting point? (a) A (b) B (c) C (d) D (e) E The graph below represents the relationship between distance and time for an object moving in a straight line. According to the graph, the object is 3 AP Physics Name_______________________ Mrs. Tsarevsky (a) (a) motionless (b) moving at a constant speed (c) decelerating (d) accelerating 4 AP Physics Name_______________________ Mrs. Tsarevsky Problem 1. An object starts moving along a straight line in the positive direction. The graph shows its position from the starting point as a function of time. position (m) 10 B 5 A 0 C D 5 10 0 5 10 15 20 time (s ) 25 30 a. Find the object’s velocity between 0 s and 5 s. b. What was the instantaneous velocity of the object at the end of the eighth second? Explain. c. During which interval(s) did the object move in the negative direction? Explain. d. What was the displacement of the object between 0 s and 20 s? Explain. e. What was the distance that the object traveled between 0 s and 20 s? Explain. f. At which time did the object reverse direction? Explain. 5 AP Physics Name_______________________ Mrs. Tsarevsky Problem 2. The graph below illustrates the velocity of an object as a function of time. Answer the questions a through e and show all work. a) What is the average velocity within the section C of the graph? b) What is the acceleration within the section E of the graph? c) When does the object come to rest? d) When does the object reverse the direction of its motion? e) What is the displacement of the object between 4 s and 7 s? 6 AP Physics Name_______________________ Mrs. Tsarevsky 7