A runner starts at the beginning of a track and runs at a constant speed of 18 km / h. After 6 minutes, a second runner starts at the same point, and his speed is 21 km / h, following the same track. How long will it take for the second runner to catch up with the first? Hint: when the second runner catches up with the first, they will have both covered the same distance. Remember the formula [distance] = [speed] x [time]

A runner starts at the beginning of a track and runs at a constant speed of 18 km / h. After 6 minutes, a second runner starts at the same point, and his speed is 21 km / h, following the same track. How long will it take for the second runner to catch up with the first? Hint: when the second runner catches up with the first, they will have both covered the same distance. Remember the formula [distance] = [speed] x [time]

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter2: Motion In One Dimension

Section: Chapter Questions

Problem 48P: A commuter train travels between two downtown stations. Because the stations are only 1.00 km apart,...

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A commuter train travels between two downtown stations. Because the stations are only 1.00 km apart, the train never reaches its maximum possible cruising speed. During rush hour the engineer minimizes the time interval t between two stations by accelerating at a rate a1 = 0.100 m/s2 for a time interval t1 and then immediately braking with acceleration a2 = 0.500 m/s2 for a time interval t2. Find the minimum time interval of travel t and the time interval t1.
A runner with a good awareness of her pace runs along a path of unknown length at a speed of 0.275 mi/min and then walks back to her starting point at a speed of 0.0500 mi/min. She neglects to note her time for each part of her path, but does measure the total round trip time to be 60.0 min. How far did she run? Do not include the walking distance
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