# Physics I week 8 patsol

Lab Report                                                    Name: ____________________

Section: ___________________

## EXPERIMENT:   Simple Machine - Lever

Experiment 1:

DATA TABLE 1: Fulcrum at _______ cm

 Trial Load (Mass) Distance of Loadfrom fulcrum Effort(Mass) Distance of Effortfrom fulcrum Ratio:Effort Distance/Load Distance 1 1 quarter 1 quarter 2 2 quarters 1 quarter 3 3 quarters 1 quarter 4 4 quarters 1 quarter

Experiment 2: Part 1 - First-class lever:

DATA TABLE 2: First-class Lever, Fulcrum at _____ m

 Trial Load(Mass, g) Load(Mass, N) Load distance,m Mass of500-gSpring scale Spring scale reading, N EffortForce, N EffortDistance, m M.A. 1 62g = 0.61N 2 62g = 0.61N 3 62g = 0.61N

Example Data Table

 Trial Load(Mass, g) Load(Mass, N) Load distance,m Mass of500-gSpring scale Spring scale reading, N EffortForce, N EffortDistance, m M.A. 1 100 1 0.3 62g = 0.61N 10g =0.1N 0.71N .45 1.41 2 153 1.5 0.3 62g = 0.61N 45g =0.44N 1.05N .45 1.42

Checking results: Workin = Workout or 1N*0.3m = 0.71N*.45m

*   MA = 1/0.71 = 1.41

Experiment 2: Part 2 - Second-class lever:

DATA TABLE 3: Second-class Lever, Fulcrum at _____ m

 Trial Load(Mass, N) Load distance,m EffortForce, N EffortDistance, m M.A. Example 1.47 0.2 80g = 0.78N .90 1.9 1 2 3 4 etc

Experiment 2: Part 3 - Third-class lever:

DATA TABLE 4 (Third-class Lever), Fulcrum at _____ m

 Trial Load(Mass, N) Load distance,M EffortForce, N EffortDistance, m M.A. Efficiency 1 2 3 Average

Calculations:

1.      In Experiment 1 calculate the ratios of the measured distances; i.e. the rations of Effort Distance/Load Distance

2.      In Experiment 2, Parts 2, 3 and 4 convert grams as needed to Newtons.

3.      In Parts 2, 3, and 4 calculate M.A. for each trial of each lever type.

Questions:

1. In Experiment 1 you calculated the ratios of the measured distances, i.e. the ratios of Effort Distance/Load Distance.  What is the significance of these ratios?  How did your calculations compare to your expectations?

1. The spring balance is reasonably accurate for determining the load mass.  However, the spring balance weighs 62 grams. Explain how to use the Workin = Workout principle to verify the mass of the spring balance.

1. After examining the 1st class lever data what kind of general statement can be made with regards to mechanical advantage and the relationship of load distance to effort distance?

1. What happens to the mechanical advantage for 2nd class levers as the load moves further away from the fulcrum?

1. What is the significance of the mechanical advantage of class 3 levers?

1. What class lever is represented by a fishing pole?  Why?

1. What kind of lever is represented by an oar used in rowing?  Why?

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