Recent content by knownothing

Homework Statement A 50-meter rope weighing 2 N/m supports a piano weighing 600 N. Find the work done in lifting the piano 25 meters 2. Relevant equation. None of the calculus equation, techniques covers this type of question with mass/length involved.The Attempt at a Solution I know the...

I don't get why the article in the FIRST link says Bernoulli is more practical than Newton.

So the energy input from the net force is taken care of by the "PV" part. The conservation of energy is more about "1/2mv^2+mgh"??

People say Beenoulli equation is just a statement of conservation of energy. But there must be a external force. Otherwise, the fluid won't move. Is it like you push the fluid and let its momentum carry it?

What does mean as in the definition of streamline that "streamlines in a flow field have no mass flow crossing them"?

What do people use to measure fluid velocity? Do they place a piece of paper and let it get blown by the air and measure its velocity?

I am trying to learn how hydrofoil works. A big part of it is Bernoulli's principles. I found this http://web.mit.edu/2.972/www/reports/hydrofoil/hydrofoil.html on MIT webisite. There are two explanation for how it works: 1. The conservation of linear momentum or Newton's third law.If water...