Viscosity Definition and 254 Threads

Hi, I am Tsering and am studying in the Mahindra UWC of India. I am doing a physics extended essay on How the cross section area of an object(cylinder) will affect the rate of slowing down of the object when dropped from a certain height into a fluid (water in my case). I will try to find the...

The human heart is able to power viscous blood through ~100,000 miles of narrow capillaries in less than a minute. Do the capillaries themselves provide a substantial fraction of the needed impulse?

A tank of large area is filled with water to a depth of 0.6m. A hole of 6m^2 cross section in the bottom allows water to drain out in a continuous stream. What is the rate at which water flows out the tank in m^3/s? This is how I figure the problem should be solved: Q=...

Did some research on the net and found most information saying it is caused by viscosity and friction, I can understand that in stuff like water but I can't really see how that would hold true for air, could somebody explain it to me or point me to a definitive explanation of the effect?