Concept explainers
Two students are canoeing on a river. While heading upstream, they accidentally drop an empty bottle overboard. They then continue paddling for 60 minutes, reaching a point 2.0 km farther upstream. At this point they realize that the bottle is missing and, driven by ecological awareness, they turn around and head downstream. They catch up with and retrieve the bottle (which has been moving along with the current) 5.0 km downstream from the turnaround point, (a) Assuming a constant paddling effort throughout, how fast is the river flowing? (b) What would the canoe speed in a still lake be for the same paddling effort?
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
University Physics with Modern Physics, Volume 2 (Chs. 21-37); Mastering Physics with Pearson eText -- ValuePack Access Card (14th Edition)
Additional Science Textbook Solutions
The Cosmic Perspective Fundamentals (2nd Edition)
Conceptual Integrated Science
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Glencoe Physical Science 2012 Student Edition (Glencoe Science) (McGraw-Hill Education)
Lecture- Tutorials for Introductory Astronomy
Cosmic Perspective Fundamentals
- Jonathan is trying to cross the Capilano river in his kayak starting at a location (point O) where the width of the river is 100 m. Starting from rest at point O, he rows in the y- direction with an acceleration (ay) of 0.08 m/s². The flowing river provides an additional acceleration (a,) of 0.02 m/s² in the x-direction. The kayak reaches paint B on the other river bank located at a distance d from point A (which is directly opposite to point O) in time t, as shown in the figure below. Compute d and t. 100 m Od 50 m, t 50s Od 25 m, t 25 s Od 25 m, t 50 s Od 50 m, t 75 sarrow_forwardA river flows due south with a speed of 2.0 m/s. A man steers a motorboat across the river. The river is 800 m wide. In which direction should the motorboat head in order to reach a point on the opposite bank directly east from the starting point? (The boat's speed relative to the water is 4.2 m/s.) To solve for this problem I did theda=arctan(-2.0+4.2)=-25.46 but since it is north of east I got theda=25 degrees, but it says that I have the wrong answer. What am I doing wrong?arrow_forwardYou are the captain of the John Paul Jones, Class-A Battleship on your way to kill the alien ship on the North side of Oahu, Hawaii. Your ship travels 10.36km [W650S] and then 5.60 km [S450W] to meet up with the alien ship. Determine your ship’s total displacement.arrow_forward
- A river is 1 km wide and flows at a velocity of 1.5 km/h. You want to cross straight to the other side of the river by swimming at a velocity of 2.5 km/h.In what direction you should swim? What time will take you to cross the river?arrow_forwardA kayaker needs to paddle north across a 100-mm-wide harbor. The tide is going out, creating a tidal current that flows to the east at 2.0 m/sm/s. The kayaker can paddle with a speed of 3.0 m/sm/s. In which direction should he paddle in order to travel straight across the harbor? How long will it take him to cross?arrow_forwardFor this problem, you can think of the jet stream as a river of air. Across the United States, the jet stream usually moves from west to east. We will assume that the jet stream is moving in its usual direction at 9.00 x 101 km/hr. On a particular day, you need to pilot a plane from one city to another that is 4.50 x 102 km directly to the south. The top speed of the aircraft in still air is 285 km/hr. (a) Make a sketch to represent what is happening in this problem. Label all quantities that you know. (b) Using cardinal directions (north, east, south, west) to give a heading, which direction should you aim the plane to reach the city directly to the south at top speed? (c) How fast (in km/hr) would you be moving relative to the ground? (c) How much time (in hr) will it take you to reach your destination?arrow_forward
- A field biologist is studying the migration patterns of northern gannets (a type of seabird). On one particular day, she records that they fly 5.0 km northeast, then turn toward to the south of east by 30◦ and fly 4.0 km in the new direction. How far east of their original position are the birds?arrow_forwardYou are a member of a geological team in CentralAfrica. Your team comes upon a wide river that is flowing east. Youmust determine the width of the river and the current speed (the speedof the water relative to the earth). You have a small boat with an outboardmotor. By measuring the time it takes to cross a pond where thewater isn’t flowing, you have calibrated the throttle settings to the speedof the boat in still water. You set the throttle so that the speed of the boatrelative to the river is a constant 6.00 m/s. Traveling due north acrossthe river, you reach the opposite bank in 20.1 s. For the return trip, youchange the throttle setting so that the speed of the boat relative to thewater is 9.00 m/s. You travel due south from one bank to the other andcross the river in 11.2 s. (a) How wide is the river, and what is the currentspeed? (b) With the throttle set so that the speed of the boat relativeto the water is 6.00 m/s, what is the shortest time in which you couldcross the river,…arrow_forwardA satellite in outer space is moving at a constant velocity of 21.2 m/s in the +y direction when one of its onboard thruster turns on, causing an acceleration of 0.330 m/s² in the +x direction. The acceleration lasts for 44.0 s, at which point the thruster turns off. (a) What is the magnitude of the satellite's velocity when the thruster turns off? m/s (b) What is the direction of the satellite's velocity when the thruster turns off? Give your answer as an angle measured counterclockwise from the +x-axis. ° counterclockwise from the +x-axisarrow_forward
- A car is 2.54 km west of a traffic light at t = 0 and 5.91 km east of the light at t = 6.00 min. Assume the origin of the coordinate system is the light and the positive x direction is eastward. Express your answers in units of km. What is the car’s position at t = 0?arrow_forwardA golfer hits a shot to a green that is elevated 2.50 m above the point where the ball is struck. The ball leaves the club at a speed of 17.0 m/s at an angle of 46.0° above the horizontal. It rises to its maximum height and then falls down to the green. Ignoring air resistance, find the speed of the ball just before it lands. V = i 18.38 m/sarrow_forwardA jetliner can fly 6.8 hours on a full load of fuel. Without any wind it flies at a speed of 3.24 x 10² m/s. The plane is to make a round-trip by heading due west for a certain distance, turning around, and then heading due east for the return trip. During the entire flight, however, the plane encounters a 75.9-m/s wind from the jet stream, which blows from west to east. What is the maximum distance (in kilometers) that the plane can travel due west and just be able to return home? Number Units ◄►arrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON