# Tag Info

Accepted

### If air was the same density as water, but still a gas, could you swim in it?

Yes, but not very well. If air were dense enough to swim in, assuming it remained in its gaseous phase, its compressibility would play a significant role. Even if air was the same density as water, ...
• 156
Accepted

### Why rain drops are spherical while water droplets on a glass surface are flat?

The answer is surface tension. When a droplet falls through the air, you only have one type of boundary that you need to account for (water-air $\sigma_{WA}$). In contrast, for a droplet on a flat ...
• 187
Accepted

### Buoyancy basics

The intuitive way to think about these types of buoyancy problems is in terms of the pressure due the heads of the fluids. Starting with the stated set up, the pressure under the ice cube due to the ...
• 6,182
Accepted

### How does Shear Force on a fluid in a vessel reaches an equilibrium if molecules are free to make contact?

The force being always perpendicular to the walls is not contradictory with the impact being not perpendicular. Think of a billiard table without friction. The angle of incidence will be equal to the ...
• 16.7k
1 vote

### Buoyancy basics

Divide the world into 3 parts. 1) The ice cube, 2) the fluid, and 3) enough fluid to fill the hole if the ice cube was not there. If you only had 1) or 3), they would fall down because of their weight....
• 41.1k
1 vote
Accepted

### Buoyant force on a stick making an angle theta with the vessel

Divide the underwater world into two parts - the water and the stick. Suppose the water disappeared, leaving the stick. The force on the stick would be the weight of the stick. Suppose you replaced ...
• 41.1k
1 vote
Accepted

### Does the compressibility of a fluid depend on its height?

Compressibility is undeniably an intrinsic property of a material, including fluids like water. It reflects the inherent ability of the material to resist volume reduction under applied pressure. As ...
• 67
1 vote
Accepted

### Understanding Pressure Transmission and Lift Mechanics in a Hydraulic Lift

First: pressure in fluids an gases is the same in all direction, so your "downward pressure does not exist. Say the thin tube is left, so you have a downward force F1 on the left piston, this ...
• 6,362
1 vote