Physics Activity #4 Physics Activity #4

9/30/149/30/14

Objective:Objective:

To measure the acceleration of gravity To measure the acceleration of gravity in the lab, by using two different in the lab, by using two different methods.methods.

Pre LabPre Lab::

Use the “Acceleration and Distance” Use the “Acceleration and Distance” formula and solve for a.formula and solve for a.

Given: d = ½ a Given: d = ½ a · t· t22

Solve for aSolve for a

Materials:

Ping Pong ball 2 Meter Sticks Stopwatch

Procedures: (Part 1)1.1. Find a location suitable for dropping your Find a location suitable for dropping your

ping pong ball to minimize the relative ping pong ball to minimize the relative fraction of time it takes to start and stop fraction of time it takes to start and stop the stopwatch.the stopwatch.

2.2. Measure the distance the object will fall - Measure the distance the object will fall - in meters. The tennis ball should start in meters. The tennis ball should start from 0.75 m and reach 2.00 m by 0.25 m from 0.75 m and reach 2.00 m by 0.25 m increments increments

3.3. Time the object's fall 5 times from each Time the object's fall 5 times from each distance and record in the data table.distance and record in the data table.

*** NOTE: The person that drops the ball should also time it!!! ***

Data: [in Excel]Drop

Distance (m)

Time 1

(s)

Time 2

(s)

Time 3

(s)

Time 4

(s)

Time 5

(s)

Ave. Time

(s)

0.75

1.00

1.25

1.50

1.75

2.00

In Excel or by calculatorIn Excel or by calculator

Calculate:Calculate:Average Average timestimesAccelerationAcceleration at each height at each height Final Final velocityvelocity as it hits the ground as it hits the ground

Lab Day 2Lab Day 2

10/1/1410/1/14

Title and NamesTitle and Names

Objective:Objective:

To measure the acceleration of gravity To measure the acceleration of gravity in the lab, by using two different in the lab, by using two different methods.methods.

Materials: (Part 1)

Ping Pong ball 2 Meter Sticks Stopwatch

Materials: (Part 2)

Go Motion SensorGo Motion Sensor Ping Pong BallPing Pong Ball ComputerComputer

Lab Day 3Lab Day 3

10/2/1410/2/14

ReviewReview

Check off and go overCheck off and go over

Procedures:Procedures: (Part 2) (Part 2)1.1. Turn on the computer & open up “Logger Pro”Turn on the computer & open up “Logger Pro”

2.2. Plug in the Go Motion SensorPlug in the Go Motion Sensor

3.3. Place sensor on groundPlace sensor on ground

4.4. Hold ping pong ball over the sensor between Hold ping pong ball over the sensor between 1.5 - 2.0 m and just off to the side 1.5 - 2.0 m and just off to the side

5.5. Click on “Collect” wait 1 second then drop the Click on “Collect” wait 1 second then drop the ball ball without moving your handwithout moving your hand

6.6. Once the ball hits the ground click on “Stop”Once the ball hits the ground click on “Stop”

7.7. Save you data EXCEL (time and position only) Save you data EXCEL (time and position only) as part of your lab reportas part of your lab report

Data: (Part 2)Data: (Part 2)

A GOOD data trialA GOOD data trial Copy and paste time and position data Copy and paste time and position data

into Excelinto Excel Calibrate time and position to zeroCalibrate time and position to zero Calculate the velocity in ExcelCalculate the velocity in Excel

Graphs: (Part 2)Graphs: (Part 2)

2 Graphs in Excel2 Graphs in Excel Trendlines should be on both graphsTrendlines should be on both graphs d-t graphd-t graph

Poly. 2 trendlinePoly. 2 trendline With the equationWith the equation

v-t graphv-t graph Linear trendlineLinear trendline With the equationWith the equation

AnalysisAnalysis

Find the percent error for all trials (6 total)Find the percent error for all trials (6 total) Where g = -9.80 m/sWhere g = -9.80 m/s22 (actual value) (actual value)

Conclusion:Conclusion: [In [In paragraph form]paragraph form]

Compare the 2 methods for finding the Compare the 2 methods for finding the acceleration of gravityacceleration of gravity

Compare you percent errors from part 1 Compare you percent errors from part 1 to part 2 (was one method more accurate to part 2 (was one method more accurate then the other)then the other)

Explain what your graphs meanExplain what your graphs mean What errors were in this activity?What errors were in this activity?