Car Racing

Andrea Boyer, Paxton Jones, Eric Tabor, Chris Tippitt

The Group

• Andrea Boyer – concept, journalist/editor, calculations

• Paxton Jones – concept, construction, supplier• Eric Tabor – concept, construction, supplier• Chris Tippitt – concept, construction, supplier

Design Overview

• Purpose: to start an electronic device• Materials used: tubing, wood, wire, ball

bearing, popsicle sticks

Calculations

Velocity of the impact of the ball bearing:mgh = (1/2)mvf

2 + (1/2)IW f2

mgh = (1/2)mvf2 + (1/2)((2/5)mr2) (v2/r2)

gh = (1/2) vf2 + (1/5) v2

gh = (7/10) vf2

vf = [(10/7)(gh)] 1/2 vf = [(10/7)(32.2 ft/s2)(2.625 in)] ½ vf = 30.1 ft/s2

Calculations, cont.

∑T = I αr(F)(sin θ) = (1/3) mr2 αr(mg)(sin θ) = (1/3) mr2 α(g)(sin θ) = (1/3) r2 αα = [(3g)(sin θ)] / r = [(3)( 32.2 ft/s2)

(sin(39.27))] / (15.5 in)α = 3.95 in/s2

Issues

• The ball bearing did not travel smoothly down the wooden ramp we originally planned to use

• Setting up the plastic tubing in a way so that the ball bearing would travel

• Determining what device we wanted to trigger

Conclusion

• Trial and error is crucial in creating a device such as this

• Teamwork plays a major factor in projects• This project allowed us to put everything that

we learned in 151 to use