Title Is Written for Physical Clarity. Experiment 2 Would Be a Boring, Bad Title

Name

Date

Hillside Acceleration

(Title is written for physical clarity. “Experiment 2” would be a boring, bad title)

Introduction: A skateboard is launched to roll up a constant slope incline, and along its way, it stops for an instant at maximum altitude and then rolls back down the hill. By measuring its location at regular time intervals, facts about the motion can be quantified.

(The introduction is brief and just tells people about what the event looked like. It is optional but very helpful.)

Objective: For the times that included upward motion and downward motion, the objective is to determine the skateboard’s numerical value of acceleration.

(This objective is obviously not the same as your objective forExperiment #1 or #2, but it is similar. I am posting an example here; I’m not going to write your lab report for you. You write your objective unique to Experiment #2 when it’s time to do Experiment #2. It should be obvious in Experiment #2 that you are setting out to find the acceleration of a freely falling thing that started from rest. The “from rest” part is an important detail, because when you do Write-up #1, that part is not true. Always watch out for important, brief, physical details.)

Data: The following raw data values were measured on 9/13/12 where the symbol x means position which means distance from a motion sensor mounted at the bottom of the hill and this motion sensor measures distances up the hill.

(Notice that since x is in the data chart, it is good to define what it means physically. A diagram could help.)

Analysis:

Columns are added that will produce an instantaneous velocity chart versus time. To get instantaneous velocity, the following sample calculation is shown:

For the time halfway between 0.1 and 0.2 sec, AKA 0.15 sec,

v = x/t = (3.47 m – 2.69 m)/(0.2 s – 0.1 s) = 7.80 m/s

7.8 m/s occurs at 0.15 sec. The other velocities were done just like this and are tabulated:

(It should be obvious to anyone who has paid attention that the math method shown above is not what is done on Experiment #2. Remember, this document is an example of any random write-up’s layout. It is not a how-to for Experiment #2 specifically. We went over Experiment #1’s methods in class.)

A plot of the v versus t is shown in Page 3(This is the reporter speaking clearly again.) Since it is roughly linear, its best-fit line is drawn. The slope of this best-fit line is the best estimate of acceleration.

Slope = -1.48 m/s/s (work shown on graph.(Is it? Ask in class.))

Acceleration = -1.48 m/s/s

Conclusion: The skateboard’s acceleration was -1.48 m/s/s. This is weaker than g which makes sense, since an angled hill represents weaker than full-strength gravity. The measuring and analysis has failed to achieve the part of the objective that said to quantify the acceleration for something that includes uphill and downhill motion.

(This writer wrote prematurely, since he/she collected incomplete data that ultimately could not achieve the stated objective. However, given no choice, since the assignment was due and he/she had to have some write-up, it is good that his/her conclusion honestly states what his/her numbers say. He/she did not achieve the objective. He/she got a numerical acceleration for a motion that was uphill but not downhill as well.)