Essential University Physics (3rd Edition)
3rd Edition
ISBN: 9780134202709
Author: Richard Wolfson
Publisher: PEARSON
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Textbook Question
Chapter 5, Problem 27E
You’re investigating a subway accident in which a train derailed while rounding an unbanked curve of radius 150 m, and you’re asked to estimate whether the train exceeded the 35-km/h speed limit for this curve. You interview a passenger who had been standing and holding onto a strap; she noticed that an unused strap was hanging at about a 15° angle to the vertical just before the accident. What do you conclude?
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Please consider this question: A train derailed while rounding an unbanked curve of radius 150 meters. A passenger on the train during the accident noticed that an unused strap was hanging at about a 15 degree angle to the vertical just before the derailment. How fast was the train moving at the time of the derailment? This is based on problem 27 of chapter 5 of Wolfson's Essential University Physics (3rd edition). The book itself has the answer 58 km/hour, which seems wrong to me. I keep coming up with something more like 71 km/hour. Can you make any sense of that?
A car is driving along a level and unbanked circular track of diameter d=0.54km at a constant speed of v=21.2m/s.
Write an expression for the magnitude of the acceleration of the car in terms of the given parameters.What is the magnitude, in meters per squared second, of the acceleration of the car?Write an expression for the minimum coefficient of friction between the car's tires and the road that is required in order to keep the car going in a circle in terms of the given parameters.What is the value of the minimum coefficient of friction between the car's tires and the road that is required in order to keep the car going in a circle?
You are the technical consultant for a car-chase sequence in an action movie. In a certain part of the scene, the director wants a car to round a certain curve while braking from 66 miles per hour to rest before it travels 290 feet along the curve. You measure the radius of the curve to be 590 feet. Is this scene possible? Defend your response and suggest an alternative scene if it is not possible.
Answer: Reduce speed to 22 meters per second or use a concrete road.
Potentially useful coefficients of friction: Tires on dry concrete (mus = 1.0, muk = 0.7); Tires on asphalt (mus = 0.6, muk = 0.4)
Chapter 5 Solutions
Essential University Physics (3rd Edition)
Ch. 5.1 - A roofers toolbox rests on an essentially How does...Ch. 5.2 - In the figure below weve replaced one of the hands...Ch. 5.3 - You whirl a bucket of water around in a vertical...Ch. 5.4 - The figure shows a logging vehicle pulling a...Ch. 5 - Compare the net force on a heavy trunk when its...Ch. 5 - The force of static friction acts only between...Ch. 5 - A jet plane flies at constant speed in a vertical...Ch. 5 - In cross-country skiing, skis should easily glide...Ch. 5 - Why do airplanes bank when turning?Ch. 5 - Why is it easier for a child to stand nearer the...
Ch. 5 - Gravity pulls a satellite toward Earths center. So...Ch. 5 - Explain why a car with ABS brakes can have a...Ch. 5 - A fishing line has a 20-lb breaking strength. Is...Ch. 5 - Two blocks rest on slopes of unequal angles,...Ch. 5 - Youre on a plane undergoing a banked turn, so...Ch. 5 - A backcountry skier weighing 700 N skis down a...Ch. 5 - Two forces, both in the x-y plane, act on a...Ch. 5 - Two forces act on a 3.1-kg mass that undergoes...Ch. 5 - At what angle should you tilt an air table to...Ch. 5 - A skier starts from rest at the top of a 24 slope...Ch. 5 - A tow truck is connected to a 1400-kg car by a...Ch. 5 - Studies of gymnasts show that their high rate of...Ch. 5 - Find the minimum slope angle for which the skier...Ch. 5 - Section 5.2 Multiple Objects Your 12-kg baby...Ch. 5 - If the left-hand slope in Fig. 5.30 makes a 60...Ch. 5 - Suppose the angles shown in Fig. 5.30 are 60 and...Ch. 5 - Two unfortunate climbers, roped together, are...Ch. 5 - Suppose the Moon were held in its orbit not by...Ch. 5 - Show that the force needed to keep a mass m in a...Ch. 5 - A 940-g rock is whirled in a horizontal circle at...Ch. 5 - Youre investigating a subway accident in which a...Ch. 5 - A tetherball on a 1.55-m rope is struck so that it...Ch. 5 - An airplane goes into a turn 3.6 km in radius. If...Ch. 5 - Movers slide a 73-kg file cabinet along a floor...Ch. 5 - A hockey puck is given an initial speed of 14 m/s....Ch. 5 - Starting from rest, a skier slides 100 m down a 28...Ch. 5 - A car moving at 40 km/h negotiates a 130-m-radius...Ch. 5 - Prob. 34PCh. 5 - A block is launched with initial speed 2.2 m/s up...Ch. 5 - In the process of mitosis (cell division), two...Ch. 5 - A 14.6-kg monkey hangs from the middle of a...Ch. 5 - A camper hangs a 26-kg pack between two trees...Ch. 5 - A mass m, undergoes circular motion of radius R on...Ch. 5 - Patients with severe leg breaks arc often placed...Ch. 5 - Riders on the Great American Revolution...Ch. 5 - A 45-kg skater rounds a 5.0-m-radius turn at 6.3...Ch. 5 - When a piano turns, it banks as shown in Fig. 5.35...Ch. 5 - You whirl a bucket of water in a vertical circle...Ch. 5 - A child sleds down an 8.5 slope at constant speed....Ch. 5 - The handle of a 22-kg lawnmower makes a 35 angle...Ch. 5 - Repeal Example 5.4, now assuming that the...Ch. 5 - A bat crashes into the vertical front of an...Ch. 5 - The coefficient of static friction between steel...Ch. 5 - A bug crawls outward from the center of a CD...Ch. 5 - A 310-g paperback book rests on a 1.2-kg textbook....Ch. 5 - Children sled down a41-m-long hill inclined at 25....Ch. 5 - In a typical front-wheel-drive car, 70% of the...Ch. 5 - A police officer investigating an accident...Ch. 5 - A slide inclined at 35 takes bathers into a...Ch. 5 - You try to move a heavy trunk, pushing down and...Ch. 5 - A block is shoved up a 22 slope with an initial...Ch. 5 - At the end of a factory production line, boxes...Ch. 5 - Youre in traffic court, arguing against a speeding...Ch. 5 - A space station is in the shape of a hollow ring,...Ch. 5 - In a loop-the-loop roller coaster, show that a car...Ch. 5 - Find an expression for the minimum frictional...Ch. 5 - An astronaut is training in an earthbound...Ch. 5 - You stand on a spring scale at the north pole and...Ch. 5 - Driving in thick fog on a horizontal road, you...Ch. 5 - A block is projected up an incline at angle . It...Ch. 5 - A 2.1-kg mass is connected to a spring with spring...Ch. 5 - Take k = 0.75 in Example 5.11, and plot the...Ch. 5 - Repeat the preceding problem for an arbitrary...Ch. 5 - Moving through a liquid, an object of mass m...Ch. 5 - Suppose the object in Problem 70 had an initial...Ch. 5 - A block is launched with speed v0 up a slope...Ch. 5 - A florist asks you to make a window display with...Ch. 5 - Youre al the state fair. A sideshow barker claims...Ch. 5 - One of the limiting factors in high-performance...Ch. 5 - Figure 5.39 shows an apparatus used to verify...Ch. 5 - A spiral is an ice-skating position in which the...Ch. 5 - A spiral is an ice-skating position in which the...Ch. 5 - A spiral is an ice-skating position in which the...Ch. 5 - A spiral is an ice-skating position in which the...
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