The Inertial Balance
The Inertial Balance
The inertial balance, a simple device for measuring the inertial mass of different objects independent of gravity, is shown below. The balance measures mass by using it’s inertia … that is, it’s resistance to acceleration. The more mass on the balance, the slower it will swing.
Procedure:
1. Clamp the balance to a table as shown. Try to clamp it in an out of the way place and not on the side of the room where people are always walking by.
2. Measure the period of the empty balance. Do this by measuring the time for 10 swings, and dividing by 10 to get the time per swing. Since the period of the balance is very short, it is difficult to count the vibrations visually. Hold a small piece of paper near one of the steel strips and count the audible snaps made by the paper when the blade just touches it. Small swings (about an inch or so) work best.
3. Add one of the thin rectangular plates to the balance, and repeat the measurements of step #2. Mass the plate on an electronic balance, record the mass in grams.
4. Continue in this manner, adding strips to the balance until you have a total of 6 strips in the balance. Be sure to measure the actual mass of each strip with the electronic balance.
5. Sketch a graph of mass on the horizontal axis, and period on the vertical axis. You graph should be roughly linear. Redo any data points obviously in error.
6. Take an object of unknown mass, like a small clamp, and measure its period. Refer to your graph, and using the graph determine the mass that corresponds to that period.
7. Measure the actual mass on the unknown using the electronic balance. Compare the two masses and calculate a percent difference.
Your Lab Report
(aka What to turn in)
This lab report will be in memo format. A memo format lab report is a report like that you would turn into your boss if you were working in an industry setting. Your report must be TYPED and in
The inertial balance, a simple device for measuring the inertial mass of different objects independent of gravity, is shown below. The balance measures mass by using it’s inertia … that is, it’s resistance to acceleration. The more mass on the balance, the slower it will swing.
Procedure:
1. Clamp the balance to a table as shown. Try to clamp it in an out of the way place and not on the side of the room where people are always walking by.
2. Measure the period of the empty balance. Do this by measuring the time for 10 swings, and dividing by 10 to get the time per swing. Since the period of the balance is very short, it is difficult to count the vibrations visually. Hold a small piece of paper near one of the steel strips and count the audible snaps made by the paper when the blade just touches it. Small swings (about an inch or so) work best.
3. Add one of the thin rectangular plates to the balance, and repeat the measurements of step #2. Mass the plate on an electronic balance, record the mass in grams.
4. Continue in this manner, adding strips to the balance until you have a total of 6 strips in the balance. Be sure to measure the actual mass of each strip with the electronic balance.
5. Sketch a graph of mass on the horizontal axis, and period on the vertical axis. You graph should be roughly linear. Redo any data points obviously in error.
6. Take an object of unknown mass, like a small clamp, and measure its period. Refer to your graph, and using the graph determine the mass that corresponds to that period.
7. Measure the actual mass on the unknown using the electronic balance. Compare the two masses and calculate a percent difference.
Your Lab Report
(aka What to turn in)
This lab report will be in memo format. A memo format lab report is a report like that you would turn into your boss if you were working in an industry setting. Your report must be TYPED and in