**ANALYSIS**

**At this point, DOUBLE CHECK to make sure that all data entries are
expressed in SI units (meters, kilograms, seconds).**

**1.** In cell **C30**, enter the number "1". You need a
serial number for each trial, so begin with mouse down at **C30**
and drag down through cell **C36**. Then use **EDIT...FILL...Series**.
Click **OK** on the dialog box, and **C30:C36** should contain
the number of washers used in each trial (1 through 7).

**2.** In cell **E30**,
enter "**= C30 * $G$11 * 9.8**" to calculate
the washer's weight in trial 1. This calculation takes the number of washers
used in this trial and multiplies by the mass of each washer times the
acceleration due to gravity to give the weight of the washer. Use
**EDIT...FILL....Down** as before to populate cells **E30:E36**.

**3.** Use the mouse to select all the cells from **D30:E36**,
that is all the acceleration and falling mass data, including the headings.

Select the x-y scatter icon from the top Toolbar.

Click on the chart itself.

Click on the legend and hit

**Delete**.From the

**View**menu, select the**Formatting Palette**if it is not already present.Select

**Chart Title**from the**Title**pull-down menu and fill it in.Next select titles for the

**Horizontal**and**Vertical**axes and fill them in.Use the mouse to size the chart and to locate it from cells

**B41**to**I60**.

**4.** Click on any one of the data points.

Choose

**Chart...Add Trendline**from the menu.Under the

**Options**tab, choose**Display equation on chart**. The equation of the best straight line fit to the data will appear on the chart.

**5.** From this fitting equation, record the values of
the slope and the intercept
in cells **F62** and** F64**, respectively. Ideally, the slope should
be equal to the total mass of all 7 washers __plus__ the glider.
We know however, from **Equation (1)** in the Introduction that the
"effective" mass of the pulley also enters in as part of the slope.

**HINT: **You
can set up the spreadsheet to calculate this value: the total mass is recorded
in cell **G13**, and the fitted value in **F62**.

Select cell

**F66**, where the answer is to appear.Type "

**=ABS(G13 - F62)/G13 * 100**". The**ABS**function takes the absolute value of the difference. The difference is then divided by the measured value and multiplied by 100 to give a percentage.

**6.** Answer **Questions 1** through **4** on the
**Worksheet**.

**7.** Print out of the **Worksheet** and turn it in to your
instructor.