Experimental Procedure

In this experiment, each student has their own equipment and will be taking data independent of their partner.

Figure 1

1) Prepare for the experiment.
Record the physical characteristics of your meter stick (width, thickness, mass). Set up the apparatus as in Figure 1.
The clamp should be close to the edge of the table. Begin the experiment with the meter stick at its longest overhang length.

2) Prepare a data section in your notebook for both a rough graph and a data table. A rough graph is used to visualize the data as you are recording them

• On the right side of you notebook, prepare a data table with columns for
  overhang length, undeflected distance and deflected distance to floor. In the data table also include a result column for deflection [(undeflected distance) - (deflected distance)]

• Do a rough measurement of what will be a typical maximum deflection value (with the longest overhang length)

• On the graph paper of you notebook's left side, prepare a graph with axis scales (estimated from a sample experiment determining extremes of the data). Horizontal (x-axis) graph scale will be 1-100cm for overhang length. Vertical (y-axis) scale will start a 0cm to some value larger than the maximum deflection determined.

3) For a selected overhang length L, measure and record:

• the un-deflected distance to the floor at the end of the meter stick.
• the deflected distance to the floor of the meter stick loaded with a 400 g mass

For this experiment, measure all data in centimeters and be sure to record uncertainties with all your measurements (uncertainties are always part of the data). As you record the data into your table, calculate the deflection and draw this data point on your graph.

4) Repeat step 3 for at least 10 different values of overhang length L.
Ensure that some your data correspond to  overhang lengths that yield deflections of less than 1 cm. Note that the un-deflected distance to the floor must be measured for each value (consider why). For each measurement ensure that you record the value into your data table and also, at the same time, show the data point on your graph. Note that zero overhang length is also a data point (an issue arises as to the accuracy of this point).

Rough graphs (or graphs that are drawn while recording data) have multiple benefits. As one is conducting an experiment, one can visually see the data trends and thus can make judgments during the experiment. With data not following the expected trend, one might redo the experiment at that value or do additional experiments around that value. The graph will also help you judge how much data is needed.