Consider a steel sphere (SG = 7.85) of diameter 2 cm,dropped from rest in the water at 208C. Assume a constant dragcoefficient CD = 0.47. Accounting for the sphere’s hydrodynamicmass, estimate (a) its terminal velocity and (b) thetime to reach 99 percent of terminal velocity. Comparethese to the results when hydrodynamic mass is neglected,Vterminal ≈ 1.95 m/s and t99% ≈ 0.605 s, and discuss.

Consider a steel sphere (SG = 7.85) of diameter 2 cm,dropped from rest in the water at 208C. Assume a constant dragcoefficient CD = 0.47. Accounting for the sphere’s hydrodynamicmass, estimate (a) its terminal velocity and (b) thetime to reach 99 percent of terminal velocity. Comparethese to the results when hydrodynamic mass is neglected,Vterminal ≈ 1.95 m/s and t99% ≈ 0.605 s, and discuss.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.29P: Air at 20C flows at 1 m/s between two parallel flat plates spaced 5 cm apart. Estimate the distance...

See similar textbooks

Similar questions

The drag of an airfoil (Fig.) increases considerably ifyou turn the sharp edge around 180° to face the stream. Canyou explain this?
For those who think electric cars are sissy, Keio University inJapan has tested a 22-ft-long prototype whose eight electricmotors generate a total of 590 horsepower. The “Kaz” cruisesat 180 mi/h (see Popular Science, August 2001, p. 15). If thedrag coefficient is 0.35 and the frontal area is 26 ft2, what percentageof this power is expended against sea-level air drag?
A ship is 125 m long and has a wetted area of 3500 m2.Its propellers can deliver a maximum power of 1.1 MWto seawater at 20°C. If all drag is due to friction, estimatethe maximum ship speed, in kn.
The so-called Rocket Man, Yves Rossy, fl ew across the Alps in2008, wearing a rocket-propelled wing-suit with the followingdata: thrust = 200 lbf, altitude = 8,200 ft, and wingspan = 8 ft(http://en.wikipedia.org/wiki/Yves_Rossy). Further assume awing area of 12 ft2, total weight of 280 lbf, CDq = 0.08 for thewing, and a drag area of 1.7 ft2 for Rocket Man. Estimate themaximum velocity possible for this condition, in mi/h.
In gliding (unpowered) flight, the lift and drag are in equilibriumwith the weight. Show that if there is no wind, theaircraft sinks at an angletan θ ≈drag/liftFor a sailplane of mass 200 kg, wing area 12 m2, and aspectratio 11, with an NACA 0009 airfoil, estimate (a) the stallspeed, (b) the minimum gliding angle, and (c) the maximumthe distance it can glide in still air when it is 1200 mabove level ground.
A buoyant ball of specific gravity SG < 1 dropped intowater at inlet velocity V0 will penetrate a distance h andthen pop out again, as in Fig. Make a dynamicanalysis of this problem, assuming a constant drag coefficient,and derive an expression for h as a function ofthe system properties. How far will a 5-cm-diameterball with SG = 0.5 and CD ≈ 0.47 penetrate if it entersat 10 m/s?
Consider wind at 20°C and 1 atm blowing past a chimney30 m high and 80 cm in diameter. If the chimney may fractureat a base bending moment of 486 kN?m, and its dragcoeffi cient based on frontal area is 0.5, what is the approximatemaximum allowable wind velocity to avoid fracture?(a) 50 mi/h, (b) 75 mi/h, (c) 100 mi/h, (d) 125 mi/h,(e) 150 mi/h
Aerodynamics NACA 747A415, chord is 180 cm 1) What is the location of favorable pressure gradient of the upper surface, measured from LE? 2) What is the location favorable pressure gradient of the upper surface, measured from TE?
The 2013 Toyota Camry has an empty weight of 3190 lbf,a frontal area of 22.06 ft2, and a drag coefficient of 0.28. Itsrolling resistance is Crr ≈ 0.035. Estimate the maximumvelocity, in mi/h, this car can attain when rolling freely atsea level down a 4° slope.
An airplane has a mass of 19,550 kg, a wingspan of 20 m,and an average wing chord of 3 m. When flying in the air ofdensity 0.5 kg/m3, its engines provide a thrust of 12 kN against an overall drag coefficient of 0.025. What is itsapproximate velocity?(a) 250 mi/h, (b) 300 mi/h, (c) 350 mi/h, (d) 400 mi/h,(e) 450 mi/h
5. At 30000ft, estimate the magnitude of transonic drag rise. Using this estimate, calculate the maximum velocity of the airplane at this altitude. Assume drag-divergence Mach number of 0.82 and d(D/D₁)/dM = 14.3 where D₁=1750lb is drag at Mach number 0.9 and D₂ = 4250lb at Mach number 1. 6 Estimate maximum range at 30000€ Also calculate the flight speed to obtain this
Consider the Gulfstream IV flying at Mach = 0.35. Calculate thrust required given an altitude of 30,000-ft, assuming weight of 73,000-lb. Airplane data: S = 950 ft2, AR = 5.92, ??? = 0.015, and K = 0.08 a. The thrust required at 30,000-ft. (in pounds)