The air outside the straw, pushing down on the water in the glass, weighs enough to hold the water up inside the straw. The water will stay
there as long as no air can get into the top of the straw
, where its weight can push the water back down to the level in the glass.
Why does the water stay in the straw rather than fall down?
Thanks for your help! Answer 1: What’s going on is that the water in the straw is
pushed into the straw by the air pressure outside of the straw
. As long as the pressure outside is able to overcome the force of gravity, the liquid will stay in the straw.
Why does water stay in a straw when you cover one end?
It’s a basic demonstration of the forces of nature. … Sealing the top of a straw with your finger stops air entering and exerting a
downward force on the liquid
, leaving only the upwards force of air pressure from below. This upwards force is stronger than the force of gravity pulling down on the liquid.
Why does water stick to the straw?
When you suck air from the straw,
less air pushes on the water inside
the straw than on the water outside of it. This imbalance causes more water to be pushed into the straw. The water will rise until the pressure created by the water column in the straw equals the air pressure difference.
How does the straw trick work?
The
liquid rises in
the straw, to exactly the same height as the liquid in the glass. That’s because the atmosphere is pushing down on the liquid in the glass. The atmosphere pushes the liquid in the glass up into the straw.
How do you close one end of a straw?
Tear the wrapping off half of the straw
, so that one end is exposed. Put the exposed end in your mouth, take aim, and blow! The wrapper shoots off the other end, like a dart from a blowgun. (Do not do this at close range, and do not aim at anyone’s face, please.)
What force is opposing gravity to hold the water in the end of the straw?
What force is opposing gravity to hold the water in the end of the straw? The force acting upward is
air pressure
. The force acting downward is gravity (obviously). When you put your finger on top of the straw you are trapping the air above the liquid in.
What is the longest straw you can drink from?
Fermat’s Library on Twitter: “The longest straw you can drink from is
approximately 10.3 m (33.8 ft) long
… “
Is there an upper limit to how long a straw can theoretically be and still work as a drinking straw?
The greater external pressure pushes the liquid up the straw and into your mouth. Is there an upper limit to how long a straw can be and still work as a drinking straw? The longest straw that could work would be
10.3 m
. What are the main assumptions in kinetic molecular theory?
How long would it take to empty a swimming pool using only a drinking straw?
The formula = (pi)* (r)*(r) * (h) = 20 * 0.0625* 3.14 = 3.4 or approx 4 cubic cm. 3. Time taken to fill and empty a straw = This seems like
about 3 seconds
to draw the water and empty elsewhere.
Why is there a limit to how long your straw can be?
~10.3 meters
is the theoretical limit – that’s for perfect vacuum. … Still, humans can’t make perfect vacuum using their mouths, so practically even a 6 meter long straw would make you sweat hard. Also, the inner diameter of the tube matters too.
How is it possible to drink through a straw?
When you drink from a straw, you
create a little space of low pressure inside your mouth and in the top of the straw
. Then the air outside the straw pushes down on the surface of the drink and forces the liquid up through the straw and into your mouth.
What is the main cause of capillarity?
Adhesion of water to the walls of a vessel
will cause an upward force on the liquid at the edges and result in a meniscus which turns upward. … Capillary action occurs when the adhesion to the walls is stronger than the cohesive forces between the liquid molecules.
Why does a straw with a hole in it not work properly?
The air pressure is the same inside and out. When you drink through the straw, you
seal your lips against the straw and then you use your lungs and mouth to reduce the air pressure in your mouth
. You do this by expanding your mouth or lungs. … This also allows air to enter, preventing the straw from working properly.
Is it true you get drunk faster through a straw?
Many people think drinking alcohol with a straw will get you drunk faster. … That’s because it’s more convenient to drink with a straw. As a result, you might get drunk faster due to the increased intake of alcohol.
The straw, however, has no effect on your rate of alcohol absorption
.
