Week 9

Lab Report                                                    Name: ____________________

                                                                                    Section: ___________________

EXPERIMENT:   Simple Machine – Lever

Experiment 1:

DATA TABLE 1: Fulcrum at _______ cm

Experiment 2: Part 1 – First-class lever:

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

Example Data Table

Checking results: Work_in = Work_out 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

Experiment 2: Part 3 – Third-class lever:

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

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 Work_in = Work_out principle to verify the mass of the spring balance.

1. After examining the 1^st 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 2^nd 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?