A farmer uses cables and winch pullers B and E to plumb one side of a small barn. If it is known that the sum of the moments about the x-axis of the forces exerted by the cables on the barn at Points A and D is equal to 4728 lb ft, determine the magnitude of TDE when TAB = 255 lb.

PY 205 with Daniel Dougherty Week 1 Chapter 1 1/12/2016 Theory – broader, more detailed and can give quantitatively testable predictions, often with great precision Law – certain, concise but general statements about how nature behaves Principle- less general statements o Scientific laws are descriptive because they describe how mature behaves Uncertainty and percent uncertainty o Ratio of uncertainty to the measured value X 100 to make it a percent o Ex: 8.8 +/- .1cm .1/8.8 X 100 = 1% Significant figures o 0 is a placeholder o Ex: 80 one significant figure since 0 does not count o RULE: number of significant figures in the last number should be the s