Concept explainers
Julie drives 100 mi to Grandmother's house. On the way to Grandmother's, Julie drives half the distance at 40 mph and half the distance at 60 mph. On her return trip, she drives half the time at 40 mph and half the time at 60 mph.
a. How long does it take Julie to complete the trip to Grandmother's house?
b. How long does the return trip take?
Want to see the full answer?
Check out a sample textbook solutionChapter 2 Solutions
College Physics: A Strategic Approach Technology Update, Books a la Carte Edition & Modified Mastering Physics with Pearson eText -- ValuePack Access . Chapters 1-16 and 17-30 (3rd Edition)
Additional Science Textbook Solutions
Cosmic Perspective Fundamentals
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
The Cosmic Perspective Fundamentals (2nd Edition)
University Physics with Modern Physics (14th Edition)
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Physics: Principles with Applications
- An express train passes through a station. It enters with an initial velocity of 22.0 m/s and decelerates at a rate of 0.150m/s2 as it goes through. The station in 210.0 m long. (a) How fast is it going when the nose leaves the station? (b) How long is the nose of the train in the station? (c) If the train is 130 m long, what is the velocity of the end of the train as it leaves? (d) When does the end of the train leave the station?arrow_forwardA commuter backs her car out of her garage with an acceleration of 1.40m/s2 . (a) How long does it take her to reach a speed of 2.00m/s2 ? (b) If she then brakes to a stop in 0.800 s, what is her acceleration?arrow_forwardAn object is at x = 0 at t = 0 and moves along the x axis according to the velocitytime graph in Figure P2.40. (a) What is the objects acceleration between 0 and 4.0 s? (b) What is the objects acceleration between 4.0 s and 9.0 s? (c) What is the objects acceleration between 13.0 s and 18.0 s? (d) At what time(s) is the object moving with the lowest speed? (e) At what time is the object farthest from x = 0? (f) What is the final position x of the object at t = 18.0 s? (g) Through what total distance has the object moved between t = 0 and t = 18.0 s? Figure P2.40arrow_forward
- A cyclist rides 8.0 km east for 20 minutes, then he turns and heads west for 8 minutes and 3.2 km. Finally, he rides east for 16 km, which takes 40 minutes. (a) What is the final displacement of the cyclist? (b) What is his average velocity?arrow_forwardAn object that moves in one dimension has the velocity-versus-time graph shown in Figure P2.52. At time t = 0, the object has position x = 0. a. At time t = 5 s. is the acceleration of the object positive, negative, or zero? Explain. b. At time t = 8 s, is the object speeding up, showing down, or moving with constant speed? Explain. c. Write an expression for the position of the object as a function of time. Explain how you use the graph to obtain your answer. d. Use your expression from part (c) to determine the time (if any) at which the object reaches its maximum position. Check your results by examining the graph. Hint: To get started with finding the maximum of a function, take the derivative and set it equal to zero.arrow_forward(a) A light-rail commuter train accelerates at a rate of 1.35m/s2 . How long does it take to reach its top speed of 80.0 km/h, starting from rest? (b) The same train ordinarily decelerates at a rate of 1.65m/s2 . How long does it take to came to a stop from its top speed? (c) In emergencies, the train can decelerate more rapidly, coming to rest from 80.0 km/h in 8.30 s. What is its emergency acceleration in meters per second sqquared?arrow_forward
- A student drives a moped along a straight road as described by the velocity-versus-time graph in Figure P2.12. Sketch this graph in the middle of a sheet of graph paper. (a) Directly above your graph, sketch a graph of the position versus time, aligning the time coordinates of the two graphs. (b) Sketch a graph of the acceleration versus time directly below the velocity-versus-time graph, again aligning the time coordinates. On each graph, show the numerical values of x and ax for all points of inflection. (c) What is the acceleration at t = 6.00 s? (d) Find the position (relative to the starting point) at t = 6.00 s. (e) What is the mopeds final position at t = 9.00 s? Figure P2.12arrow_forwardA truck was running on a highway at 25 m/s and then it stopped. If it takes to 2.5 min to stop (A) what is its acceleration? (B) How far will it travel before stopping?arrow_forwardYou’re driving down the highway late one night at 20 m/s when a deer steps onto the road 35 m in front of you. Your reaction time before stepping on the brakes is 0.50 s, and the maximum deceleration of your car is 10 m/s2.a. How much distance is between you and the deer when you come to a stop?b. What is the maximum speed you could have and still not hit the deer?arrow_forward
- A horse travels 65 km/hr with a distance of 5.98 km . a. How long does the horse travels? b. What is the new speed of the horse if he travels twice his time travelled?arrow_forwardAlan leaves Los Angeles at 8:00 am to drive to San Francisco, 400 mi away. He travels at a steady 50 mph. Beth leaves Los Angeles at 9:00 am and drives a steady 60 mph.a. Who gets to San Francisco first?b. How long does the first to arrive have to wait for the second?arrow_forwardA subway train starts from rest at a station and accelerates at 3 m/s2 for 10seconds. It then runs at constant speed for 90 seconds, and then slows down at-4 m/s2 until it stops at the next station.a. What is the train’s velocity after the initial acceleration?b. How far did the train travel during the initial acceleration?c. How many seconds did the train take to decelerate?d. What is the distance between the two stations?arrow_forward
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning