You will need
  • - spirometer;
  • - the balloon;
  • - threads;
  • - the pelvis;
  • - wide plank;
  • - measuring Cup.
To determine the amount of light can be in a medical facility. To do this, doctors used a special device – the spirometer.
To measure vital capacity of lungs you will need a balloon, yarn or twine, a large container of water, a wide Board and some measuring utensils. For greater accuracy, it is better to have a graduated beaker. Place the container in the tub and fill with water to the brim.
Take the ball, smooth it between your hands, removing air. This is done for better accuracy of the experiment. However, given that the air in the ball quite a bit and the measurement error will be some fraction of a percent, this stage can be neglected.
Take a maximally deep breath, then firmly press the opening of the balloon to your lips and exhale to the limit. Loop the end of the balloon and tightly tie the string or twine.
Then place the inflated balloon on the surface of the containers with water standing in the tub, gently press the top plate and begin to press for as long as the plate does not lie on the edges of the tank, and the bulb will not be submerged. Try to keep it not twisted (that is why the Board needs to be wide).
Of course, some of the water out, because it replaced the air enclosed in the volume of your ball. Now your task is to determine how much water is poured. (By the way, a similar problem was solved long ago, the great scientist Archimedes to determine whether pure gold made crown of king Hiero).
Remove pressure plate, remove the ball from partially empty containers. Then using the graduated cylinder, filling it and pouring the water into the tank, determine what volume of water will need to it again reached the edges. This volume is equal to the vitality of the lungs.