Fluid Dynamics

Raindrops falling under gravity do not gain very high velocity due to air resistance. As raindrops fall through the atmosphere, they experience a force opposite to their direction of motion, which slows them down. The balance between gravity and air resistance limits the maximum velocity that raindrops can achieve.

Fluid statics and fluid dynamics were significantly advanced by several key figures throughout history. Archimedes, in ancient Greece, is often credited with foundational work in fluid statics, particularly with his principle of buoyancy. In the 17th century, scientists like Blaise Pascal and Daniel Bernoulli made major contributions to fluid dynamics, with Bernoulli's principle being a cornerstone in understanding fluid behavior. Their collective work laid the groundwork for modern fluid mechanics.

Low surface tension means high wetting as it represents low contact angle. It is therefore very easy for a low surface tension water / liquid to wet the surface ( usually solid) and get rid of the dirty in a same way a surfactant does unlike a high surface tension liquid which can't wett the surface containing the dirty.... ( answered by MR BANDA) #NOTE i stand to be corrected if any error was made

These products are lipids and caseins.

Density at 12,000 feet (or 3658 m), is 0.05302 lbm/ft^3 (or 0.8491 kg/m^3).

about 70 bar (1000 PSI)

Yes. A single gas particle experiences gravitational force.

There is no drag in a vacuum to act against the acceleration.

The pressure will be the sum of pressures of oil and water:

p = rowater g hwater + rooil g hoil

Specific gravity of 0.8 of oil means it's 0.8 times as dense as water:

rooil = 0.8 rowater

Pressure will be then:

p = g (rowater hwater + 0.8 rowater hoil), or numerically:

p = 4355.64 Pa

If the water is flowing, like in a river or stream, then the cork goes with the flow.

But if it's in a pond, and ripples are rippling out and getting bigger but the cork

is just bobbing up and down, then you have learned something very important

about transverse waves: The material in transverse waves, like the water in

the ripples, or the ground in a seismic surface wave, or the wave in the rope

when you snap one end, just moves back and forth across the line of the

wave's progress. But although energy is carried along, the material stays

where it is and just bobs across the line.

Computational fluid dynamics software, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyse problems that involve fluid flows.

Only if they are so old you won't even want to think about eating them.

If you only put one hole, the liquid can flow out, but air cannot flow in to replace it, so the liquid soon stops running because it's filled up the hole totally. You have to replace the lost space with air to keep it running, so you need a second hole.

The velocity at each point in the fluid is a vector. If the fluid is compressible, the divergence of the velocity vector is nonzero in general. In a vortex the curl is nonzero.

The barometric leg in a barometric condenser is required to create a seal that prevents the ingress of air into the condenser. This seal helps maintain a vacuum within the condenser, which is essential for efficient steam turbine operation. The barometric leg allows air and non-condensable gases to be removed from the system to maintain the desired vacuum level.

The air pressure is the same, inside or outside the paper bag.

A solid metal ball would sink into the very viscous liquid, a hollow metal ball would float. The speed of descent is dependent on the density of the liquid.

Yes, you can give the 12th science exam as an external student.

The buoyant force acts in the opposite direction of gravity, pushing an object upwards when it is submerged in a fluid. This force is proportional to the volume of the displaced fluid by the object and helps objects float or rise in a fluid, enabling objects to achieve buoyancy.

increases with speed

You may mean a "close-coupled pump" in which case, that is a pump which is mounted directly on the same shaft as the driving motor: i.e. there is no baseplate or coupling to join the two shafts, drive and driven, and the pump hangs off the notor frame. A centrifugal pump is a type of pump where the liquid is forced to travel by an impeller which is inside a close-fitting chamber, or "volute" - it is probably the most common industrial and domestic pump type.