Gravity Vehicle 1 Gravity Vehicle San Diego Regional

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Gravity Vehicle 1 Gravity Vehicle San Diego Regional

Gravity Vehicle 1 Gravity Vehicle San Diego Regional

Gravity Vehicle The Goal Build a ramp and a vehicle powered solely by its

Gravity Vehicle The Goal Build a ramp and a vehicle powered solely by its own gravitational potential energy to reach a target as quickly and accurately as possible. 2

Gravity Vehicle Parameters • Vehicle Mass: <=2. 0 kg • No electric or electronic

Gravity Vehicle Parameters • Vehicle Mass: <=2. 0 kg • No electric or electronic components • Must move as a whole – no tethers, anchors, etc. • Only wheels may touch the track • No size limit for vehicle alone – however, in ready-to-run, vehicle and ramp must be no more than 50. 0 cm x 50. 0 cm long x 100. 0 cm high 3

Gravity Vehicle Dowel 4 • ~¼” round wood • within 1. 0 cm of

Gravity Vehicle Dowel 4 • ~¼” round wood • within 1. 0 cm of floor • at least 20. 0 cm above floor • <= 0. 5 cm in front of dowel except wheel >= 20 cm <= 1 cm <= 0. 5 cm

Gravity Vehicle Brakes • Distance precision depends on brakes. • Common Types: • String

Gravity Vehicle Brakes • Distance precision depends on brakes. • Common Types: • String • Wingnut 5

Ramp Gravity Vehicle • Shape: • Flat - Easy to build • Curved -

Ramp Gravity Vehicle • Shape: • Flat - Easy to build • Curved - smoother transition • Build frame with the shape you want, attach a thin sheet • Materials • 1/8” MDF • Sheet Metal • Ease transition to floor to reduce error • Don’t let dowel scrape floor 6

Release Mechanism Gravity Vehicle • Launch using unsharpened #2 pencil • May be a

Release Mechanism Gravity Vehicle • Launch using unsharpened #2 pencil • May be a part of release mechanism • May extend beyond dimension limits • Ideas: • Drill hole in Ramp, “hang” Vehicle from pencil. Pull out pencil to release. • Cut hole in Ramp, use some other kind of mechanism. • Place release mechanism at top of Ramp (no holes required). 7

Gravity Vehicle Adding Mass • Added mass helps overcome friction • Height of added

Gravity Vehicle Adding Mass • Added mass helps overcome friction • Height of added mass raises vehicle center of mass => higher potential energy 8

Gravity Vehicle Examples 9

Gravity Vehicle Examples 9

Gravity Vehicle Practice Log 10 • At least 4 parameters • At least 10

Gravity Vehicle Practice Log 10 • At least 4 parameters • At least 10 runs Target Distance Vehicle Distance from Target FIXED • Target Distance • Vehicle Distance from Target • Run Time Run time Additional Parameter(s) SELECTED • # axle turns • Alignment

Track 11 Timed Target Point 1. 00 m Gravity Vehicle Start Line 9. 00

Track 11 Timed Target Point 1. 00 m Gravity Vehicle Start Line 9. 00 – 12. 00 m 0. 50 m Line 8. 50 m Line • Smooth, level, and hard surface • Lines and points are marked with/on 1” tape • Distance between 9 and 12 meters • Regionals: 0. 50 meter increments • State: 0. 25 meter increments • Nationals: 0. 05 meter increments

Gravity Vehicle The Competition • 8 minutes to setup for and start 2 runs

Gravity Vehicle The Competition • 8 minutes to setup for and start 2 runs • No electric tools except calculator • Remove alignment or targeting devices before run • Must not touch/push vehicle or ramp when launching 12

Scoring Gravity Vehicle • The Run Score for each run: 2 pts. /cm x

Scoring Gravity Vehicle • The Run Score for each run: 2 pts. /cm x Vehicle Distance + 1 pt. /sec x Run Time + Penalties • Vehicle Distance is point-to-point • Accuracy emphasized over speed. • Only go as fast as you can brake accurately. 13

Gravity Vehicle Scoring – Issues Failed Run • Vehicle moves but does not pass

Gravity Vehicle Scoring – Issues Failed Run • Vehicle moves but does not pass the 0. 50 m Timing Line • Time or Distance not measurable • Not started within 8 minutes • Crosses 0. 5 m line, but not 8. 5 m line => Time = 60 seconds Non-Run • If the Vehicle does NOT move, not counted as a Failed Run. May try again Incomplete Practice Log = 250 point penalty No Practice Log = 500 point penalty 14

Gravity Vehicle Scoring – Tiers 1: A clean run. No violations 2: Competition violation

Gravity Vehicle Scoring – Tiers 1: A clean run. No violations 2: Competition violation 3: Construction violation 4: Two failed runs 5: Failure to impound 15

Venue Gravity Vehicle • Miramar • Student Services Lunch Area (tentative) • USD –

Venue Gravity Vehicle • Miramar • Student Services Lunch Area (tentative) • USD – Not announced 16

Gravity Vehicle Suggestions • Build slightly less than maximum size & weight • Practice

Gravity Vehicle Suggestions • Build slightly less than maximum size & weight • Practice on different types of floors • Clean the floors • Axle bearings reduce friction • Dowels are the most frequent construction violation • Be careful not to accidentally triggering release 17

Gravity Vehicle Resources • Problem Solving / Technology CD • Gravity Vehicle Digital DVD

Gravity Vehicle Resources • Problem Solving / Technology CD • Gravity Vehicle Digital DVD • www. soinc. org/gravity-vehicle • www. soinc. org/events/rules-clarifications • scilympiad. com/san-diego-so/Qn. As • scioly. org/forums/viewforum. php? f=315 18