Starting from the appropriate momentum and energy differential equations, evaluate the Nusselt number for both surfaces of a parallel-plane channel in which there is fully developed laminar flow (both velocity and temperature developed) and in which there is heating from both surfaces but the heat flux from one surface is twice the heat flux of the other surface, and again when the heat flux from one surface is five times the heat flux from the other surface. The heat flux per unit length of duct is constant. Your equation should produce what you expect in simpler cases too. Does a symmetric heat flux condition yield Nu 8.23 (as =5.39? This last question should be used as a sanity check for your derivation was derived in class) and does one side heated/other adiabatic yield Nu

more than, less

less than, more

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

i think the answer would be reserve.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.