Lab 5：Working with Spreadsheets

Purpose: To get familiar with electronic spreadsheets by using them in some simple applications.

Equipment: Computer with EXCEL software.

Part 1:

Create a simple spreadsheet that calculates the values of the following function:

f(x)=Asin(Bx+C)

Initially choose value for of A= 5, B= 3 and C= π/3 (1.047).  

Create a column for values of x that run from zero to 10 radians in steps of 0.1 radians. Similarly, create in the next column the corresponding values of f(x) by copying the formula shown above down through the same number of rows (100 in roll).

Our data of two columns

spreadsheet first 20 rows with formulas 

Then copy and paste our data into the graphing program. Put appropriate labels on the horizontal and vertical axes of the graph. Use Curve Fit to find a function that best fit the data.

 The function that best fit the our data

The best fit function: y= 5Sin(3x +1.05)-1.49×10^(-10)

Part 2: 

Repeat the above process for a spreadsheet that calculates the position of a freely falling particle as a function of time. Start off with g= 9.8m/s^2, vo= 50m/s, xo= 1000m and △t= 0.2s.

The formula for free fall: f(t)= ro+vo△t+(1/2)a(△t)^2 

 We assuming the direction of  vo  positive.

(i)When g is positive:

f(t)=1000+ 50t+ (1/2)× 9.8t^2

Our data of two columns when g is positive

Use Curve Fit to find a function that best fit the data:

 The function that best fit the our data when g is positive

The best fit function: f(t)= 4.9t^2+ 50t+ 1000

(ii)When g is positive:

f(t)=1000+ 50t+ (1/2)× (-9.8)t^2

Our data of two columns when g is negative

spreadsheet first 20 rows with formulas when g is negative

Use Curve Fit to find a function that best fit the data:

The function that best fit the our data when g is negative

The best fit function: f(t)= (-4.9)t^2+ 50t+ 1000 

Question: How do data from part 1 and part 2 compare to the values we start with in our spreadsheet?

       In part 1, we compare the data(A=5, B=3, C=1.05) from Curve Fit to the values(A=5, B=3, C=1.047) that we start with in our spreadsheet. In part 2, we do the same thing as initial values are "g= 9.8m/s^2, vo= 50m/s, xo= 1000m and △t= 0.2s". We find that the data from Curve fit are almost the same to the initial values.

Conclusion:
      In this experiment, we try to use electronic spreadsheet to solve problems. We practice the Excel and get familiar to it. In the future, we may use Excel to more and more. So, this experiment is a  good experience to us, that let us know how it works and how it benefits us.
      We find that the data from Curve fit are almost the same to the initial values. This experiment shows that we can utilize Excel and Graphical Fit to collect and summarize the data.
      The causes of error:
       (1) Our data are rounding values so they can't be exactly accurate.
       (2) We collect the data that have the intervals, so our result is an estimate.