Meditation Tips for Beginners. 1  Guided meditation MP3s or CDs as meditation tools. For beginners, audio guided meditations provide step-by-step instructions that help to introduce meditation in an easy and non-intimidating way. 2  Aim to have the length of your exhalations as long, if not longer, than your inhalations.
While air can be compressed more easily than water, freely flowing air acts much like waterâat least at relatively low speeds. So when you squeeze a stream of air, two things happen. The air speeds up, and as it speeds up, its pressureâthe force of the air pressing against the side of the objectâgoes down. When the air slows back down, its pressure goes back up. Why does the air speed up? Because of conservation of mass, which states that mass is neither created nor destroyed, no matter what physical changes may take place.
Click on the menu on the left to see the range of altitude.org interactive calculators. At sea level there is a pressure equivalent to 10 metres of water pressing down on all of us all the time. This is because of the weight of the air above us in the atmosphere. The important effect of this decrease in pressure is this: in a given volume of air, there are fewer molecules present. This is really just another way of saying that the pressure is lower. (This is called Boyle's law.) The percentage of those molecules that are oxygen is exactly the same: 21%.