Question

Imagine that you are having your favourite juice using a straw. Then which statement is correct?

• A. A straw works on the basis of atmospheric temperature.
• B. A straw works on the basis of atmospheric density.
• C. A straw works on the basis of Archimedes's principle.
• D. A straw works on the Bernoulli's principle.

Answer 1

The correct option is D

A straw works on the Bernoulli's principle.

Straws work on the principle of the outside atmospheric pressure pushing the fluid up the straw after you have lowered the pressure at the top of the straw (in your mouth). When you suck the air out of the straw, you decrease the pressure inside the straw, allowing the higher pressure on the rest of the surface to push the juice up the straw and into your mouth.

According to the Bernoulli's principle, as the pressure decreases, the velocity of the fluid increases.