The purpose of this lab is to compare a measured value of
the acceleration of an object due to gravity to the accepted value of acceleration
due to gravity. After comparing the measured values to the accepted value, it
is possible to see how physicists arrived at the conclusion that the
acceleration of an object due to gravity is approximately 9.80 m/s2.
In a group of five students, we taped a tripod holding a Vernier Go-Motion
Sensor to cabinets in our classroom to hold it in place. We then dropped a
pillow from the top of the Vernier Go-Motion Sensor and measured the velocity/time
(acceleration in m/s2), assuming that the acceleration is both
constant and unknown. We dropped the pillow from the top of the Vernier
Go-Motion Sensor until we had five good drops, and recorded all the data in
Logger Pro.
The equipment used for this experiment was the following:
a computer, Microsoft Word, Microsoft Excel, Logger Lite software, a tripod, a Vernier
Go-Motion Sensor, multi-purpose paper (lab paper), graph paper printed from www.incompetech.com,
a printer, black ink toner, masking tape, and a pillow with a plastic covering.
Raw Data
*bold letters denote a vector throughout the report. (position=s, deviation=d, initial velocity=vi, final velocity=vf, acceleration=a)
Do you have a headache yet?
Data Analysis
Finding the acceleration for each pillow drop required
recording all of the values for position, displacement, elapsed time, initial
velocity, and final velocity, and then using a formula to solve. Because it is
assumed that acceleration is constant, the formulas for constant acceleration
yield the values for acceleration. I used the displacement formula for constant
acceleration.
D = vi t + ½ a
t2
To find a best value for absolute deviation (Da), the
absolute deviation for each measured value of acceleration must be calculated
first. I used the equation for absolute deviation to find these values.
Da =
| MV – BV |
Using the previously calculated values for absolute
deviatio, I found the relative deviation (Dr). The best value for relative
deviation likewise could only be found by first calculating the individual
deviations for each value of acceleration from all five trials.
Dr =
Da / BV x 100
Calculating the best value for absolute error (Ea)
required subtracting the accepted value from the measured value, and allowing
the answer to be an absolute value for each measurement of acceleration, after
which all values are divided by five trials.
Ea =
| measured value – accepted value |
Is your brain exploding now?
(It's okay, the same thing happens to me in class every day.)
Why am I taking Honors Physics again?
Oh yeah, because I don't know what I want to major in yet,
so I'm trying to cover all my bases in high school
in hopes that it will earn me an acceptance letter to the Y.
I have to remind myself daily.
I won't tell you what time of night I finished this lab report.
Hoping you're doing something more fun than this,
Jess
4 comments:
Jessica...how did you have time to write this post? There are way too many distractions around you my dear. Nevertheless, your physics paper is amazing. I don't understand a thing, but it sure sounds smart.
I definately am doing something more fun than that! I'm surprised you aren't cross-eyed.
THat sounds awful!!! I LOVE your header!!!!!! HOw did you do that?!
You better get to the Y! It's the only way we'll get to see you more often.
Keep studing! Your such an amazing girl Jess!
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