1. Ready?

2. Travis Nachtrab Todd Watkins Dan Bertuso and 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

3. 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 delivered Water 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

4. Stage 1: = K f + E loss U0U0 Drink needs to cool Energy from falling bucket and friction in spool is converted to rotational kinetic energy Stage 2:Energy must be Transferred to open can and release cart U el = U f Rat trap releases potential energy of counterweight K 0 = U el Kinetic energy from ball releases spring energy from rat trap U 0 = K f Golf ball loses potential and gains kinetic energy Kinetic energy from bucket releases potential energy from golf ball K 0 = U f Rat trap releases potential energy of counterweight U 0 = K f Counterweight loses potential and gains kinetic energy U 0 = K f Kinetic energy of counterweight does work to open beverage can and releases cart K 0 = W Stage 3: U 0 = K f K 0 + F fric + U el = W Friction from towel and elasticity of bungee do work to bring bucket to a stop Potential energy is converted to kinetic and sends bucket down ramp Energy must send cart down ramp and bring it to rest

5. Problems involved… Reducing friction in reel Releasing golf ball Releasing cart down ramp Pull tab reliability The biggest problem… Lots and lots of testing

6. 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 ?