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Look Ma’ – no hands – air pressure science experiment

Riding a bicycle with no hands on the handle bars

Look Ma’ – no hands

The pushing force of air is called air pressure. The closer you are to Earth, the greater the air pressure. The farther away from Earth (in other words the higher your altitude), the less the air pressure. And remember, pressure is coming from all around us. Here’s an experiment to demonstrate the pressure of air that’s all around us.

  1. Take the coffee can and punch 3 small holes in the bottom. Also punch one hole in the plastic lid.
  2. Now fill the coffee can about 1/2 full of water and put the lid on.
  3. Place your hand over the hole and press down on the lid. Notice how the water streams out of the holes on the bottom due to the pressure you are exerting on the lid.
  4. Now slowly stop applying pressure to the lid. Notice how the stream of water stops. You can stop and start the flow of water simply by removing your finger from the hole.

When you filled the can only half full, you left some space empty. This space actually was not empty – it was filled with air. Pressure on the lid exerted pressure on this air which in turn exerted pressure on the water forcing it out of the can. When you stop pressing on the lid, and leave your finger over the hole, the pressure of the air outside the can holds the water up from the bottom.

About air pressure

Air pressure refers to the force exerted by the weight of air molecules on a surface. This force is perpendicular to the surface and is measured in units of pressure such as pounds per square inch (psi) or pascals (Pa).

Air pressure is a result of the constant movement of air molecules, which collide with one another and with surfaces. The weight of the air above a surface creates a pressure gradient, with higher pressure at lower altitudes and lower pressure at higher altitudes.

Changes in air pressure can have significant effects on weather patterns and can also impact human health. For example, low pressure systems are associated with stormy weather, while high pressure systems are generally associated with clear skies.

Air pressure is commonly measured using a barometer, which detects changes in atmospheric pressure and converts them to a numerical reading. Understanding air pressure is crucial for a variety of activities, including aviation, weather forecasting, and scuba diving.

Experiment Supplies

Supplies: Coffee can

Image Credits

In-Article Image Credits

Riding a bicycle with no hands on the handle bars via Wikimedia Commons by Richard Drdul with usage type - Creative Commons License. May 20, 2009

Featured Image Credit

Riding a bicycle with no hands on the handle bars via Wikimedia Commons by Richard Drdul with usage type - Creative Commons License. May 20, 2009

 

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