AIR, WATER AND WEATHER

AIR EXERTS PRESSURE

 

  Air pressure on everything, in all directions. if you squeeze an empty  plastic bottle and  then     release  it,  the  bottle  will  regain its  shape this  is because air enters  the  bottle and  pushes 
  the bottle and pushes  the sides out  again, if  you squeeze the bottle and then place  the cap       on,  the bottle will not take up its original shape. this because the air outside the bottle is             pressing the sides in.  air presses on our body does not get           crushed by the pressure of the air because the body too          contains air. 
   these  two experiments will show you how air presses on              everything. 
   fill a glass with water, right up to the brim. slide a stiff piece     of  paper over the top.
  press the paper down firmly. turn the glass over and remove       your hand. you will  be surprised 

   that the water and the paper do not fall down. it is because        air  from below is exerting pressure  and this pressure is              supporting the paper is position.