Fluid Statics

Objective:
Experience and calculate the buoyant force.
A:Underwater Weighting Method

   

B.Underwater Weighting Method

C: Volume of Object Method

 

 

 

 

Calculation:

 

Summary:

    1. The error of Part A mainly come from the balance and the reading on the string. It's basically a very accurate way to measure the buoyant force.

 For, Part B, we use the concept of Archimede's principle. Since the volume of the cylinder is small and the exceeded water was just about 30-40 ml, the error of this method could be very large. Therefore, Part B is not a good way to determine the buoyant force.

 For Part C, the errors come from the reading from rule.   Part C is still a good way to find the buoyant force even it is not as accurate as Part A.

2.Underwater weighting method is the most accurate.

3. If ,in Part A, the cylinder had been touching the bottom of the water container, the container would exert a force N to the cylinder. Then W=T+B+N or B=W-T-N. The value would be to low comparing to B=W-T.