Physics Activity #4
9/30/14
Objective:
 To measure the acceleration of gravity
in the lab, by using two different
methods.
Pre Lab:
 Use the “Acceleration and Distance”
formula and solve for a.
 Given: d = ½ a · t2
 Solve for a
Materials:
 Ping Pong ball
 2 Meter Sticks
 Stopwatch
Procedures: (Part 1)
1. Find a location suitable for dropping your
ping pong ball to minimize the relative
fraction of time it takes to start and stop
the stopwatch.
2. Measure the distance the object will fall in meters. The tennis ball should start
from 0.75 m and reach 2.00 m by 0.25 m
increments
3. Time the object's fall 5 times from each
distance and record in the data table.
*** NOTE: The person that drops the ball should
also time it!!! ***
Data: [in Excel]
Drop Time Time Time Time Time
Distance
1
2
3
4
5
(m)
(s)
(s)
(s)
(s)
(s)
0.75
1.00
1.25
1.50
1.75
2.00
Ave.
Time
(s)
In Excel or by calculator
Calculate:
 Average times
 Acceleration at each height
 Final velocity as it hits the ground
Lab Day 2
10/1/14
Title and Names
Objective:
 To measure the acceleration of gravity
in the lab, by using two different
methods.
Materials: (Part 1)
 Ping Pong ball
 2 Meter Sticks
 Stopwatch
Materials: (Part 2)
 Go Motion Sensor
 Ping Pong Ball
 Computer
Lab Day 3
10/2/14
Review
 Check off and go over
Procedures: (Part 2)
Turn on the computer & open up “Logger Pro”
Plug in the Go Motion Sensor
Place sensor on ground
Hold ping pong ball over the sensor between
1.5 - 2.0 m and just off to the side
5. Click on “Collect” wait 1 second then drop the
ball without moving your hand
6. Once the ball hits the ground click on “Stop”
7. Save you data EXCEL (time and position only)
as part of your lab report
1.
2.
3.
4.
Data: (Part 2)
 A GOOD data trial
 Copy and paste time and position data
into Excel
 Calibrate time and position to zero
 Calculate the velocity in Excel
Graphs: (Part 2)
 2 Graphs in Excel
 Trendlines should be on both graphs
 d-t graph
 Poly. 2 trendline
 With the equation
 v-t graph
 Linear trendline
 With the equation
Analysis
 Find the percent error for all trials (6 total)
 Where g = -9.80 m/s2 (actual value)
Conclusion: [In paragraph
form]
 Compare the 2 methods for finding the
acceleration of gravity
 Compare you percent errors from part 1
to part 2 (was one method more accurate
then the other)
 Explain what your graphs mean
 What errors were in this activity?