How to Use Balloons to Lift

When a balloon is filled with a gas that is lighter than air, it will rise through the air, if the total weight of the balloon and everything attached to it is less than the weight of the air it displaces. Air does not have much mass so the lifting power of balloons is limited. Calculating the lifting power of balloons is difficult because of the large number of variables involved. But you can measure the lifting force for a typical balloon and use it to calculate the number of balloons needed to lift a small object.

• 1

  Estimate the amount of string you will need to tie each balloon to the object you are lifting. Cut this length of string and tie it to each of the five balloons. Because the strings are be attached to the balloon while it is lifting up the spring in the scale, you don't need to factor the weight of the string in your calculations.. The balloons will have to lift the strings and pull up on the scale.

• 2

  Use the strings to tie the balloons to the hook on the bottom of the spring scale. Hold the scale upside down and allow the balloons to rise and pull the spring up. Read the scale to determine how much weight the balloons can lift. Using five balloons magnifies the lift so that you can read the scale more easily.

• 3

  Divide the weight by five to determine the lift per balloon.

• 4

  Weigh the object you want to lift. Divide the weight by the average lift per balloon according to your calculations above. Add a few extra balloons to the number to ensure the lifting power of the balloons will be sufficient.

• 5

  Tie the appropriate number of balloons to the object and let go.