New High School Class: The Physics of Motorsports

Michael Czeiszperger · **Joined:** Thu Apr 09, 2009 9:35 am **Posts:** 861

Nothing like hands-on learning to get the hang of physics:

http://www.mysuncoast.com/news/manatee_ ... 0f31a.html

Hillier said it's not just about feeling the rush of cruising around a racetrack instead of being at school for these kids. It is also to help inspire the students to want to take the physics of motorsports course that Manatee School of the Arts offers, which includes a weekly visit to the track for hands on learning.

"At the finish line, we'll get a velocity," Hillier explained. "And then they're suppose to break as hard as they can for the shortest stopping distance. They'll collect the data, they'll go back to school in the next class, and they'll calculate what the g-force was of their deceleration."

Andrew Jonell · **Joined:** Mon Mar 23, 2009 6:43 pm **Posts:** 1350

Quote:

"And then they're suppose to break as hard as they can for the shortest stopping distance.

But they might get hurt!

It might be because I have a STEM background, but I found it pretty interesting to see how much energy was dissipated when braking into T1 at VIR for my first track day. I think going from 105 to 45mph over 400ft resulted in something like 350HP.

Steven Carter · **Posted:** Tue Jan 29, 2013 1:31 pm

Andrew Jonell wrote:

Quote:

"And then they're suppose to break as hard as they can for the shortest stopping distance.

But they might get hurt!

It might be because I have a STEM background, but I found it pretty interesting to see how much energy was dissipated when braking into T1 at VIR for my first track day. I think going from 105 to 45mph over 400ft resulted in something like 350HP.

Hat tip to James Short on this recommendation. Great physics book vis a vis cars and motorsports for the non-STEM types.

http://www.amazon.com/Fast-Car-Physics-Chuck-Edmondson/dp/0801898234/ref=sr_1_1?s=books&ie=UTF8&qid=1359480511&sr=1-1&keywords=fast+car+physics

Surely this class has more of a curriculum than what was described in the article--great way to get kids interested, though!

Andrew Jonell · **Joined:** Mon Mar 23, 2009 6:43 pm **Posts:** 1350

Most important thing in physics: units.

I tried to redo the calculation based on my post earlier, and had to have my finger on Wikipedia to remember the units necessary.

MPH -> meters/second
Feet -> meters
Watts -> HP

To say the least, I'm glad Google Calculator exists with all of the unit type conversions.

And if I did this right... 247.3KW = 331.6HP to brake from 105 to 45mph in a Miata at the #5 marker. (I'll wait for James to post to prove me wrong :lol:

)

BretLuter · **Posted:** Tue Jan 29, 2013 2:10 pm

I really hope they don't "break as hard as they can", or at least if they do, get it on video.

:mrgreen:

JamesShort · **Posted:** Tue Jan 29, 2013 3:15 pm

Andrew Jonell wrote:

Most important thing in physics: units.

I tried to redo the calculation based on my post earlier, and had to have my finger on Wikipedia to remember the units necessary.

MPH -> meters/second
Feet -> meters
Watts -> HP

To say the least, I'm glad Google Calculator exists with all of the unit type conversions.

And if I did this right... 247.3KW = 331.6HP to brake from 105 to 45mph in a Miata at the #5 marker. (I'll wait for James to post to prove me wrong :lol:

)

Nope, you are correct but you made some hefty assumptions: constant acceleration which is clearly not the case and no friction/aero drag (bearings all over the car are constantly converting KE to heat when you are off the throttle). So the change in kinetic energy is not solely due to heat conversion by the brakes.

I guess you assumed your car weights 2200 (998kg) because your numbers match mine almost exactly

.

EDIT: Average braking at 0.75G? That's kind weak, no? Step it up Andrew

.

Vincent Keene · **Posted:** Tue Jan 29, 2013 3:20 pm

JamesShort wrote:

[(bearings all over the car are constantly converting KE to heat when you are off the throttle).

So bearings don't do this anytime except off throttle? I've got to get me some of those bearings! :mrgreen:

JamesShort · **Posted:** Tue Jan 29, 2013 3:23 pm

Vincent Keene wrote:

JamesShort wrote:

[(bearings all over the car are constantly converting KE to heat when you are off the throttle).

So bearings don't do this anytime except off throttle? I've got to get me some of those bearings! :mrgreen:

Yeah, wasn't worded correctly, point was that the change in KE was not just due to the brakes converting KE to heat since the bearing frictional losses aid in the deceleration of the car in addition to the brakes.

Andrew Jonell · **Joined:** Mon Mar 23, 2009 6:43 pm **Posts:** 1350

JamesShort wrote:

Andrew Jonell wrote:

Most important thing in physics: units.

I tried to redo the calculation based on my post earlier, and had to have my finger on Wikipedia to remember the units necessary.

MPH -> meters/second
Feet -> meters
Watts -> HP

To say the least, I'm glad Google Calculator exists with all of the unit type conversions.

And if I did this right... 247.3KW = 331.6HP to brake from 105 to 45mph in a Miata at the #5 marker. (I'll wait for James to post to prove me wrong :lol:

)

Nope, you are correct but you made some hefty assumptions: constant acceleration which is clearly not the case and no friction/aero drag (bearings all over the car are constantly converting KE to heat when you are off the throttle). So the change in kinetic energy is not solely due to heat conversion by the brakes.

I guess you assumed your car weights 2200 (998kg) because your numbers match mine almost exactly

.

EDIT: Average braking at 0.75G? That's kind weak, no? Step it up Andrew

.

I switched up to HT-10s/DTC-60s so I can shorten it up to 300ft (~1.03G). You're spot on with all of my assumptions because the real world doesn't exist; I operate in a vacuum.

I just killed 30 minutes at work making a Physics 101 spreadsheet with all of the conversions and stuff. :v

Vincent Keene · **Posted:** Tue Jan 29, 2013 3:49 pm