initial timing experiment

phy231

Your 'initial timing experiment' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** template form

Initial Timing Experiment

You may enter any message or comment you wish in the box below:

________________ **

** ________

In this experiment you will use the TIMER program, a hardcover book, a cylinder or some other object that will roll along the book in a relatively straight line, and a ruler or the equivalent (if you don't have one, note the RULERS link on the Assignments page).

Place the book on a flat level tabletop.  You will prop one end of the book up a little bit, so that when it is released the object will roll without your assistance, gradually speeding up, from the propped-up end to the lower end.  However don't prop the end up too much.  It should take at least two seconds for the ball to roll down the length of the book when it is released from rest.

Then reverse the direction of the book on the tabletop, rotating the book and its prop 180 degrees so that the ball will roll in exactly the opposite direction.  Repeat your measurements.

In the box below describe your setup, being as specific as possible about the book used (title, ISBN) and the object being used (e.g., a solid glass marble, a small can of tomato paste (full or empty?), a ball-point pen), and what you used to prop the object up (be as specific as possible).   Also describe how well the object rolled--did it roll smoothly, did it speed up and slow down, did it roll in a straight line or did its direction change somewhat?

Note:  Don't trust this form.  Compose your answer in Notepad or a word processor, saving it every few minutes, then copy and paste it into the box.  Power could surge, your computer could malfunction, in any of a number of ways the work you put into this form could be lost.  Compose it elsewhere and keep a copy.

________________ **

I used the University Physics book from this course. 11th Edition

ISBN: 080538684

The object being used is an empty Redken aerosol hairspray bottle (super strength finishing spray) 11oz when full

The book was proped up with a stack of college ruled notebook paper 6mm thick.

The can started slowly on release and sped up as it continued smoothly down the face of the book in a straight line.

** ________

In the box below report your data.  State exactly what was measured, how it was measured, how accurately you believe it was measured and of course what the measurements were.  Try to organize your report so the reader can easily scan your data and see any patterns that might occur.

________________ **

The book face along which the can travels is 26cm long. The higher end on the stack of paper is at a height of 65mm, while the lower end is at 59mm. All measurements taken by a ruler with inch, cm, and mm markings. These are accurate to 1mm.

The first run left to right the can travelled 260mm in 2.609375 seconds

The second run left to right the can travelled 260mm in 2.734375 seconds

The third run left to right the can travelled 260mm in 2.4375 seconds

The first run right to left the can travelled 260mm in 2.4375 seconds

The second run right to left the can travelled 260mm in 2.046875 seconds

The third run right to left the can travelled 260mm in 2.125 seconds

** ________

Using your data determine how fast the object was moving, on the average, as it rolled down the incline.  Estimate how accurately you believe you were able to determine the object's average speed, and give the best reasons you can for your estimate of the accuracy.

________________ **

By adding all 6 times and dividing by 6, you get the average time it took to travel down the face of the book. 2.3984375 seconds. to find the average speed of the can you must take the 260mm length travelled and divide by the average time taken.

260mm/2.3984375seconds = 108.4039mm/s or 39.025 meters per hour

** ________

Devise and concuct an experiment to determine whether or not the object is speeding up as it rolls down the incline.  If you have set the experiment up as indicated, it should seem pretty obvious that the object is in fact speeding up.  But figure out a way to use actual measurements to support your belief.

Explain how you designed and conducted your experiment, give your data and explain how your data support your conclusions.

________________ **

By marking the halfway point on the book (130mm) and selecting the time at which the can starts, passes the halfway mark, and ends, you can average the speed it take to travel each half of the surface.

Right to left

1.59375, .828125

2.21875, .984375

1.875, .890625

Left to Right

1.5, .953125

2.03125, .84375

1.515625, .859375

In both sets of data the first number represents the time taken from start to the halfway point (130mm), the second number represents the time taken from the halfway point to the finish line. both distances are 130mm in length and are sloped equally.

The data shows that the speed being travelled from the start to the halfway point is almost half of what it is from the halfway point to the finish.

** ________

Your instructor is trying to gauge the typical time spent by students on these experiments.  Please answer the following question as accurately as you can, understanding that your answer will be used only for the stated purpose and has no bearing on your grades: 

________________ **

55 minutes

** ________


You may add optional comments and/or questions in the box below.

________________ **

&#This looks very good. Let me know if you have any questions. &#