Lab #2: Free Fall

Free Fall

Samuel
Ellis
Mia
8-31-2016

2.

To examine in the absent of all other external forces expect gravity, a falling body will accelerate at -9.8 m/s^2

3.

Theory: In physics class, we always assume gravity will be -9.8 meter per second square. In the real world, however, it doesn't always happen that way. At different location, gravity will vary from -9 meter square per second to -10 meter square per second. So in this experiment, we let gravity to be our only source of force. By letting gravity act on an object, we can determine how fast it accelerate downward. And since gravity is the only force acting on that object, the acceleration will be gravity.

 4.

1. Pull a piece of paper tape between the vertical wire and the vertical post of the device. Clip it with a weight to keep the paper "tight".

2. Turn the dial hooked up to the electromagnet up a bit.

3. Hang the wooden cylinder with the metal ring around it on the electromagnet.

4. Turn on the power on the sparker box.

5. Hold down the spark button on the sparker box.

6. Turn the electromagnet off so that the thing falls.

7. Turn off the power to the sparker thing.

8. Tear off the paper strip and set up the spark paper for the next person to get their data.

Excel:

1. select your data in columns D and E. Click on the Chart tab, then choose scatter, then Marked Scatter to give an XY (scatter) graph with the point NOT connected.

2. Use the Chart Layout tab to give appropriate titles (with unit) for your graph and your graph axes.

3. under the chart layout tab click on trendline, choose trendline option. choose a liner fit. under the options choose "display equation on chart" and "display r-squared value on charf". when you click "OK" this should give you a line and equation on the graph. Double-click on the equation on your chart. use the numbers formatting to get a reasonable number of decimal places in your answers. use the font menu to make the equation large enough that it will show up nicely when you to print or photograph your graph. 

4.Select column A and B. follow the same steps above except when you get to add trendline choose a polymonial fit of order 2.

5 & 6

(we first measure the distance between each dot(at least 14). Then input data into computer using excel, then follow the procedure above.By using linear fit, we can get an equation of the linear line. Which give up the Constance.  At the end we got speed vs time & distance vs time graph. Then we the number we got in the graph, which is 901 as our gravity Constance.

(this is the data from other groups)

8.

At the end, our calculation shows that gravity for our experiment is around 9 meter per second square. Which is lay between 9 and 10, so its normal. Gravity constance vary at different location. In conclusion, we find the acceleration of gravity by using the distance between dots and know the punch time for each dots. Then plot those data using excel and use linear fit to find gravity.