Ready?

Travis Nachtrab

Todd Watkins

Dan Bertusoand Zac Gill

We are pleased to present:

…are team 3

The second greatest

use of a Rat Trap

The first being: Killing Rats!

A group project for EF105–B2 Spring 2007

Counterweight drops wheel chock Gravity pulls cart down ramp

Ramp sends cart to end of table Cart is stopped by end plate

End plate is cushioned by bungee

Can is deliveredWater is released

Bucket fills with water Gains mass

Bucket drops and pulls string String rotates ice bucket Rotation cools beverage

Can is opened Bucket reaches bottom

Pulls retaining pin Pin releases ball

Ball rolls into rat trap Rat trap pulls another pin

Pin releases counterweight Counterweight pulls key

Key opens pull tab

Stage 1:

= Kf+ ElossU0

Drink needs to cool

Energy from falling bucket and friction in spoolis converted to rotational kinetic energy

Stage 2: Energy must be Transferred to opencan and release cart

Uel = UfRat trap releases potential

energy of counterweight

K0 = UelKinetic energy from ball releases

spring energy from rat trap

U0 = KfGolf ball loses potential and gains kinetic energy

Kinetic energy from bucket releases potential energy from golf ballK0 = Uf

Rat trap releases potential energy of counterweightU0 = Kf

Counterweight loses potential and gains kinetic energy U0 = Kf

Kinetic energy of counterweight does workto open beverage can and releases cartK0 = W

Stage 3:

U0 = Kf

K0 + Ffric + Uel = WFriction from towel and elasticity of

bungee do work to bring bucket to a stop

Potential energy is converted tokinetic and sends bucket down ramp

Energy must sendcart down ramp

and bring it to rest

Problems involved…

Reducing friction in reel

Releasing golf ball

Releasing cart down ramp

Pull tab reliability

The biggest problem…

Lots and lots of testing

The drink has been cooled, opened, and delivered.

Good times will be enjoyed by all.

This project has shown us how energy can be stored, transferred, and used

to the convenience and benefit of mankind.

Man is unique in that we have risen from the apes to make energy do our

bidding.

Questions?