Concept explainers
Consider the street pattern shown in Fig. 2–47. Each intersection has a traffic signal, and the speed limit is 50 km/ h. Suppose you are driving from the west at the speed limit. When you are 10.0m from the first intersection, all the lights turn green. The lights are green for 13.0 s each. (a) Calculate the time needed to reach the third stoplight. Can you make it through all three lights without stopping? (b) Another car was stopped at the first light when all the lights turned green. It can accelerate at the rate of 2.00 m/s2 to the speed limit. Can the second car make it through all three lights without stopping? By how many seconds would it make it or not?
Want to see the full answer?
Check out a sample textbook solutionChapter 2 Solutions
PHYSICS F/SCI.+ENGR.,V.1 (CHAP.1-20)
Additional Science Textbook Solutions
College Physics
Cosmic Perspective Fundamentals
College Physics
Life in the Universe (4th Edition)
College Physics (10th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
- A truck is traveling east at 82 km/h. At an intersection 34 km ahead, a car is traveling north at 60 km/h. (a) How long (in minutes) after this moment will the vehicles be closest to each other? b) How far apart will they be at that point (in km)?arrow_forwardDon't provide hand writing solutionarrow_forwardA car has an average highway speed of 90 km/h or 25 m/s. At this speed; how long will it take to drive to Kenora which is 190 km away? (Be sure to use common units.)arrow_forward
- A motorcyclist with a speed of 80 km / h applies the brakes to stop in 5 seconds before a traffic light, considering a constant acceleration, Calculate: a) the magnitude of his acceleration. b) the total distance traveled from when he applied the brakes to a stop. c) how fast he takes 2 seconds after applying the brakes and the distance he traveled during the first 2 seconds after braking.arrow_forwardFigure 2-42 shows a simple device for measuring your reaction time. It consists of a cardboard strip marked with a scale and two large dots. A friend holds the strip vertically, with thumb and forefinger at the dot on the right in Fig. 2-42. You then position your thumb and forefinger at the other dot (on the left in Fig. 2-42), being careful not to touch the strip. Your friend releases the strip, and you try to pinch it as soon as possible after you see it begin to fall. The mark at the place where you pinch the strip gives your reaction time. (a) How far from the lower dot should you place the 50.0 ms mark? How much higher should you place the marks for (b) 100, (c) 150, (d) 200, and (e) 250 ms? (For example, should the 100 ms marker be 2 times as far from the dot as the 50 ms marker? If so, give an answer of 2 times. Can you find any pattern in the answers?)arrow_forward36 km/h to Braking uniformly reduces the speed of a train from vị 3. V2 = 7.2 km/h during 100 seconds. Find: (1) the negative acceleration of the train; (2) the distance traveled by the train during the time the brakes are applied. B) – 0.06 m/s² ; 800 m. D) – 0.08 m/s?; 600 m. A) – 0.055 m/s? ; 900 m. C) – 0.07 m/s?; 700 m.arrow_forward
- (II) Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 0.83 s after passing his window. Roger’s room is on the third floor, 15 m above the sidewalk. (a) How fast are the balloons traveling when they pass Roger’s window? (b) Assuming the balloons are being released from rest, from what floor are they being released? Each floor of the dorm is 5.0 m high.arrow_forwardAn airplane travels 2100 km at a speed of 720 km/h and then encounters a tailwind that boosts its speed to 990 km/h for the next 2800 km. What was the total time for the trip? What was the average speed of the plane for this trip?[Hint: Does Eq. 2–11d apply?arrow_forwardIn the design of a rapid transit system, it is necessary to balance the average speed of a train against the distance between station stops. The more stops there are, the slower the train’s average speed. To get an idea of this problem, calculate the time it takes a train to make a 15.0-km tripin two situations: (a) the stations at which the trains must stop are 3.0 km apart (a total of 6 stations, including those at the ends); and (b) the stations are 5.0 km apart (4 stationstotal). Assume that at each station the train accelerates at a rate of 1.1 m/s2until it reaches 95 km/h then stays atthis speed until its brakes are applied for arrival at the next station, at which time it decelerates at - 2.0 m/s2 Assume it stops at each intermediate station for 22 s.arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningClassical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage LearningAn Introduction to Physical SciencePhysicsISBN:9781305079137Author:James Shipman, Jerry D. Wilson, Charles A. Higgins, Omar TorresPublisher:Cengage Learning
- University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University