For my AP Physics final, we have to write a paper on how something, that interests us, works and how physics applies to it. It is only a 5 page paper so I don’t have to do very extensive research and experiments.
For my topic I’m bouncing around with these three…
Aerodynamics of a bike (Zipp Dimpled Disks, aero helmets, tear drops, “dirty air”, etc.)
Carbonfiber vs. Al bikes. This is more chemisty but I’m more interested in the vibrations and riding comfort between the two.
Oakley optics. How the physics of the lenses and frame structure helps them withstand extreme conditions and hard impacts along with lense clarity.
If anyone has any suggest on these three of where I could obtain information about them or another topic that may be interesting to do.
You could do a bit on how a bicycle fork is designed so that when you lean one way, the bike turns that direction. This helps you stay up and allows you to ride with no hands!
You could also show that a fork installed backwards would do the opposite thing and make the bike more difficult to ride.
Could also delve into slowman’s favorite subjects of head tube angle, rake and trail. That should be around 5 pages.
That is an amazing idea. Do you know where I could obtain any information on that? We are allowed to have “theories” of how things work or will work so I could get away with my assumptions but hard evidence is always nice.
Do a simple topic and do it well. Aerodynamics is too vast and you want a subject you can do easily over 5 pages. Choose a simple product and go to a great depth. thi is what i look for in my students…
you can google stuff on bicycle forks and turning and find some college lectures with analysis. I’ve found some good stuff that way.
You could also discuss, the trade off between weight and aerodynamics in bicycle performance. you could use the calculators on analytic cycling to find different power curves based on climbing different slopes comparing them to the course profiles of different races.
If you want to do something like aerodynamics, I would pick just one aspect like dimples or foil shape or surface finish.
Do something on the different kinds of brakes: V-Brake, Cantilever, the new Zero gravity, discs. You got levers, applied forces, friction, and momentum…thats too much physics to miss!
You could do a bit on how a bicycle fork is designed so that when you lean one way, the bike turns that direction. This helps you stay up and allows you to ride with no hands!
You could also show that a fork installed backwards would do the opposite thing and make the bike more difficult to ride.
Could also delve into slowman’s favorite subjects of head tube angle, rake and trail. That should be around 5 pages.
Foale is an engineer who has done some really great innovative motorcycle design. The principles above are covered well in the articles on his site. He also has a book, which I have buried around here somewhere. This is a great topic for a 5 page paper imho…
A more interesting test for the Oakleys would be the lens blanks that they use – uniform thickness throughout so no irregularities in focus. Met with Jim Jannard and toured the Oakley site in 1996 – very interesting. Get you hands on a laser, split the beam with a prism and focus the 2 beams to a point about 10 feet away. Put Oakleys in front of the 2 beams – the two dots remain within one another. Put any other pair of sunglasses in front of the beams – the points split – don’t know if other manufacturers have changed their lens blanks, but the Oakley demonstration had a real impact on me in terms of optical clarity – Very simple physics, but important in terms of real-world benefits to end user and easy enough to demonstrate.
I read a book a few months ago called “Bicycling Science” which basically described the phsyics and Engineering behind every aspect of bicycling. From the unicycle to HPVs to human powered aircraft the book was very robust and very thorough. I’m a Mechanical Engineer and I was impressed with how thorough it was.
I forgot who wrote the book, but if you Yahoo! search it (I’m anti google or the use of word google in the verb format) I’m sure you can find out.
Investigate how potential energy is changed into rotational energy of a bike wheel.
Mount a bicycle so that the rear wheel turns freely using a rope. Make sure the rear wheel is off the ground and the front wheel is tied to a table to stabalize.
Strap a 2 kg mass to one of the pedals (possibly a brick)
Place a mark on the tire to visualize the rotation of the tire
Move the mass (on the pedal) to the highest point. Measure the distance from the highest point to the lowest point as the pedal turns.
Release the pedal so the mass rotates the pedal and rear wheel. Stop the mass at its lowest point and count the number of rotations the wheel makes in 10 seconds.measure to the nearest tenth of a turn
Repeat multiple trials
Now attatch a 4 kg mass and repeat produre from above.
Remove wheel and find mass and diameter of wheel
Analysis
Calculate average number of rotations for each mass
Find the number of radians the wheel turns in ten seconds for each mass. radians = 1 revolution
Find the angular velocity for each case.
Assume all the mass of the wheel is on the radius. Calculate the moment of iniertia of the wheel
I = mr^2
find the rotational kinetic energy of the wheel KE = 1/2 Im^2 (M = mass of wheel )
Find the gravitational potential energy in each case (PE = mgh)
Analysis
Potential enery should equal kinetic energy - do they? why not?
Wher did the missing energy go?
What is the percent energy lost or gained?
How did the angular velocity of the whell with the higher mass compare to the other.
Does the equation for rotational KE predict #4?
Do this investigation with trainng wheels and race wheels and report your data.
Easily 5 pages.
“Practical Physics Labs” - Peter Goodwin ; J.Weston Walsh