(Revised 10-15-01)
Lab 2: The Inclined Plane
Purpose: (Hint: Among what variables do you want to determine a relationship? What object is being tested, on what type of surface, under what changing condition(s)?
Materials: (List them)
Diagram:
Click on button for illustrated discussion on apparatus
setup:
Procedure: This lab will be conducted by groups of three
(Delineate the steps you used to complete this lab, in outline form.)
Definitions:
(Include specific vector orientations where required)
Theta (θ) –
Fwt –
FN –
FP –
EFN –
EFP –
Data Table:
Fwt
|
θ |
FN(exp) |
FP(exp) |
FN(math) |
FP(math) |
Fwt(math) |
%EFN(math)vsFN(exp) |
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15º |
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25º |
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45º |
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Sample Calculations: You must show for EACH of the three angles, the work for FN(math), FP(math), Fwt(math) = [(FNexp)2 + (FPexp)2]1/2, and %E. You must include formulas, all math steps, and units.
Conclusion:
1. Using specific examples from the data above, Explain HOW FP and FN change as θ increases, other than at 0° and 90°.
Example: θ1 to θ2 FP = _________ to ___________
FN= _________to ____________
2. As a vector quantity, should Fwt(exp) change as the angle of inclination increases? Explain, including appropriately labeled diagrams.
3. Construct five labeled diagrams depicting the relationship between FP and FWT, then between FN and FWT, as θ increases (0º, 25º, 45º, 70º, 90º). Write an explanation beneath each diagram.
4. First, discuss the relationship between the two terms in each of the following, stating specific values:
(A) FP(exp) and FP(math). Then, explain the relative agreement between these two values, in terms of lab technique employed.
(B) Fwt(exp) and Fwt(math). Then, explain any disagreement between these two values, in terms of lab techniques employed. You may not include this source of disagreement as one of the three potential sources of lab error below.
5. Why use FP(exp) and FN(exp) when calculating FWT(math)?
Express your response,
(A) in terms of mathematical validity.
(B) in terms of checking for lab technique.
6. What, specifically, will a low percentage error for FN, FP, or FWT indicate?
Three Potential Sources of Lab Error:
(state the error, state what variable(s) affected specifically, and give specific data values as substantiation)
Practice Problems:
(all problems must have completely labeled diagrams)
1. Short Answer Problems: Any one problem from #7, 10, 11, 12, 14, 15, 16.
2. A 115-lb crate is placed on an inclined conveyor belt. While packages are being removed from the top, a man pushes upward on the crate with a force of 44.93-lb, to prevent it from sliding backward.
What is the angle of the conveyor?