Fox and McDonald's Introduction to Fluid Mechanics
9th Edition
ISBN: 9781118912652
Author: Philip J. Pritchard, John W. Mitchell
Publisher: WILEY
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Textbook Question
Chapter 9, Problem 96P
A 180–hp sports car of frontal area 1.72 m2, with a drag coefficient of 0.31, requires 17 hp to cruise at 100 km/h. At what speed does aerodynamic drag first exceed rolling resistance? The rolling resistance is 1.2 percent of the car weight, and the car mass is 1250 kg. Find the drivetrain efficiency. What is the maximum acceleration at 100 km/h? What is the maximum speed? Which redesign will lead to a higher maximum speed: improving the drive train efficiency by 6 percent from its current value, reducing the drag coefficient to 0.29, or reducing the rolling resistance to 0.91 percent of the car weight?
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Chapter 9 Solutions
Fox and McDonald's Introduction to Fluid Mechanics
Ch. 9 - The roof of a minivan is approximated as a...Ch. 9 - A model of a river towboat is to be tested at 1:18...Ch. 9 - For flow over a smooth plate, what approximately...Ch. 9 - A model of a thin streamlined body is placed in a...Ch. 9 - A student is to design an experiment involving...Ch. 9 - A 1 m 2 m sheet of plywood is attached to the...Ch. 9 - The extent of the laminar boundary layer on the...Ch. 9 - Velocity profiles in laminar boundary layers often...Ch. 9 - An approximation for the velocity profile in a...Ch. 9 - Evaluate / for each of the laminar boundary-layer...
Ch. 9 - Evaluate the displacement thickness and the...Ch. 9 - Evaluate the displacement thickness and the...Ch. 9 - A fluid, with density = 1.5 slug/ft3, flows at U...Ch. 9 - Solve Problem 9.13 with the velocity profile at...Ch. 9 - Air flows in a horizontal cylindrical duct of...Ch. 9 - Evaluate the displacement thickness and the...Ch. 9 - Evaluate the displacement thickness and the...Ch. 9 - A laboratory wind tunnel has a test section 25 cm...Ch. 9 - Air flows in the entrance region of a square duct,...Ch. 9 - A flow of 68F air develops in a flat horizontal...Ch. 9 - A flow of air develops in a horizontal cylindrical...Ch. 9 - Using numerical results for the Blasius exact...Ch. 9 - Using numerical results obtained by Blasius (Table...Ch. 9 - Using numerical results obtained by Blasius (Table...Ch. 9 - A smooth flat plate 2.4 m long and 0.6 m wide is...Ch. 9 - Consider flow of air over a flat plate. 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A simple but effective anemometer to measure wind...Ch. 9 - The Willis Tower (formerly the Sears Tower) in...Ch. 9 - It is proposed to build a pyramidal building with...Ch. 9 - Calculate the drag forces on a 1/200 scale model...Ch. 9 - A circular disk is hung in an air stream from a...Ch. 9 - A vehicle is built to try for the land-speed...Ch. 9 - An F-4 aircraft is slowed after landing by dual...Ch. 9 - A tractor-trailer rig has frontal area A = 102 ft2...Ch. 9 - A 180hp sports car of frontal area 1.72 m2, with a...Ch. 9 - An object falls in air down a long vertical chute....Ch. 9 - Prob. 99PCh. 9 - A light plane tows an advertising banner over a...Ch. 9 - The antenna on a car is 10 mm in diameter and 1.8...Ch. 9 - Consider small oil droplets (SG = 0.85) rising in...Ch. 9 - Standard air is drawn into a low-speed wind...Ch. 9 - A small sphere with D = 6 mm is observed to fall...Ch. 9 - A tennis ball with a mass of 57 g and diameter of...Ch. 9 - A water tower consists of a 12-m-diameter sphere...Ch. 9 - A cast-iron 12-pounder cannonball rolls off the...Ch. 9 - A rectangular airfoil of 40 ft span and 6 ft chord...Ch. 9 - A rectangular airfoil of 9 m span and 1.8 m chord...Ch. 9 - Why is it possible to kick a football farther in a...Ch. 9 - If CL = 1.0 and CD = 0.05 for an airfoil, then...Ch. 9 - A wing model of 5 in. chord and 2.5 ft span is...Ch. 9 - A barge weighing 8820 kN that is 10 m wide, 30 m...Ch. 9 - A spherical sonar transducer with 15 in. diameter...Ch. 9 - While walking across campus one windy day, an...Ch. 9 - If the mean velocity adjacent to the top of a wing...Ch. 9 - The NACA 23015 airfoil is to move at 180 mph...Ch. 9 - A human-powered aircraft has a gross weight of 240...Ch. 9 - WiffleTM balls made from light plastic with...Ch. 9 - A model airfoil of chord 6 in. and span 30 in. is...Ch. 9 - An antique airplane carries 50 m of external guy...Ch. 9 - How do cab-mounted wind deflectors for...Ch. 9 - An airplane with an effective lift area of 25 m2...Ch. 9 - The U.S. Air Force F-16 fighter aircraft has wing...Ch. 9 - A light airplane, with mass M = 1000 kg, has a...Ch. 9 - A light airplane has 35-ft effective wingspan and...Ch. 9 - Assume the Boeing 727 aircraft has wings with NACA...Ch. 9 - Jim Halls Chaparral 2F sports-racing cars in the...Ch. 9 - Some cars come with a spoiler, a wing section...Ch. 9 - Roadside signs tend to oscillate in a twisting...Ch. 9 - Air moving over an automobile is accelerated to...Ch. 9 - A class demonstration showed that lift is present...Ch. 9 - Rotating cylinders were proposed as a means of...Ch. 9 - A baseball pitcher throws a ball at 80 mph. 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