Hi, I am doing a theoretical investigation which will be compared to an experimental I'll do later. I am trying to calculate how much time will it take an object to fall a heigh H. the object is a 5x5x5 cm cube. I have the Reynolds number as this Re=3546*Velocity; and I need both the drag coefficient and the terminal velocity.
Air density ([itex]\rho[/itex]): 1.25 kg/m3
Air Dynamic Viscosity ([itex]\mu[/itex]): 1.76E-05
Area: 25 cm3
Cube side length: 0.05 m or 5 cm
Height (H): 30m
The Attempt at a Solution
I used classic mechanics to estimate the avarage of V for a height H of 30m, and got a value of 12.15 m/s so Re=3546*12.15.
I'm stuck from here on.
I need the Drag Coefficient, and the terminal V, and at what time does the object reach the velocity.