Lung Capacity

Purpose - To measure the amount of air that can be forcedout of the lungs.

Materials - masking tape

1 gallon(4-liter) plastic milk jug with cap

tapwater plastic dishpan

2 feet (61 cm)of aquarium tubing pen

helper

Procedure

■ Place a strip of masking tape downthe side of the milk jug from top to bottom.

■ Fill the jug with water, and screwon the cap.

■ Fill the dishpan about Vz full with water.

■ Place the jug upside down in thewater, and remove the cap.

■ Have a helper hold the jug. DO NOTallow air bubbles to enter the milk jug.

■ Place one end of the aquariumtubing inside the mouth of the jug.

■ Take a normal breath and exhalethrough the tubing. Mark the water level on the tape.

■ Refill the jugwith water and return it to the dishpan.

■ Breathe in deeply and try to exhale all of theair out of your lungs through the tubing. Mark the water level on the tape.

Results The water level drops as exhaled air enters thejug. Normal breathing does not push out as much water as does deep breathing.

Why? When the air enters the jug, it pushes the waterout the opening. In normal breathing, only about one eighth of the lungs’capacity is used. During exercise, more air is taken in and exhaled, thus thereis a larger amount of air exhaled during deep breathing.

Lung Capacity