For laminar boundary layers it is reasonable to expect that δ /δt ≈ prn, where n is a positive exponent. consider laminar boundary layer flow over a flat plate with air at 100ºc and 1 atm, the thermal boundary layer thickness is approximately 15% larger than the velocity boundary layer thickness. determine the ratio of δ/δt if the fluid is engine oil (unused) under the same flow conditions. (round the final answer to two decimal place.) given: for air at 100ºc and 1 atm, pr = 0.7111. for engine oil (unused) at 100ºc, pr = 279.1

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.

An object with initial temperature 130 ∘ f is submerged in large tank of water whose temperature is 50 ∘ f . find a formula for f ( t ) , the temperature of the object after t minutes, if the cooling constant is k = − 0.2 . remember newton's law of cooling (the rate of change of temperature with respect to time is equal to k times the difference between the temperature of the object and the surrounding temperature) ! : )

To a of 4 x hz is 1. 0. mm nm nm