Lever Lab
Lab: Determine the Relationship Between the Arms of a First Class Lever

Introduction:

During this lab you will determine how one side of a first class lever and its forces relates to the other side and its forces.  What you think is the relationship?  Develop a hypothesis from what you already know.

Materials:

Procedure:

Set up your meter stick and stand such that the middle of the stick (i.e., the 50cm mark) is on the ring stand.
All measurements for distance will be the distance from the center of the meter stick.
The meter stick will have to be supported by hand to keep it on the ring stand, but it should be allowed to balance itself as much as possible.
Follow the set-ups described by the data table to fill in the blanks.
Place one hanger on one side and add the appropriate weights.
Set the hanger at the appropriate distance stated in the data table.
On the other side of the fulcrum (in Part I), add the mass and move the hanger until the level is perfectly balanced.
In Part II you will do the opposite.  You will set the hanger at the specified distance and add weights until it is perfectly balanced.
Record data each time.

Results:

Part I: Changing the distance
Side ASide B
Mass(g)Distance(cm) Work(g?cm)Mass(g)Distance(cm) Work(g?cm)
20025_______600______________
40025_______600______________
60025_______600______________
80025_______600______________
100025_______600______________
Part II: Changing the mass
Side ASide B
Mass(g)Distance(cm) Work(g?cm)Mass(g)Distance(cm) Work(g?cm)
20025______________5_______
40025______________15_______
60025______________25_______
80025______________35_______
100025______________45_______

Part II: Changing the fulcrum

Set the fulcrum at the 75 cm mark on Side B.  Now complete the data table.

Side ASide B
Mass(g)Distance(cm) Work(g?cm)Mass(g)Distance(cm) Work(g?cm)
10000 (end!)______________75 (end!)_______

Discussion:

1. As the mass increased on Side A, what happened to the distance to the fulcrum of the mass on Side B?

2.  How do the products (i.e., the Work) on Side A compare with the products on Side B?  Is there a pattern?

3. What are some factors that prevented the amount of work on both sides from being equal to one another?

4. Which equation(s) covered in class were appropriate here?