RUBE GOLDBERG: PETTING A DOGBy: Kaily, Sam, Erin, and Emily, group 2, period 10

PETTING A DOG

Sam created the initial design. After that we all added our own input.

The inspiration came from structures he sees at the farm.

It contains at least 1 of every simple machine and certain kinds like the incline plane are used multiple times.

The goal we achieved was to successfully pet a dog

PETTING A DOG

The machine starts off with by pushing a small car into dominoes

The domino is a 3rd class lever The MA for a domino is 0.22 Le= 1cm, lr= 4.5cm MA=le/lr MA=1cm/4.5cm

PETTING A DOG

Then the dominoes hit balls which slide down a ramp.

The ramp is the 1st inclined plane The MA for the inclined plane is 1.4 l= 25cm, h= 18cm, MA= l/h, MA= 25cm/18cm

PETTING A DOG

After the inclined plane the balls roll down into the funnel. Balls exit funnel onto another ramp.

MA for the 2nd inclined plane is 3.4 l= 17cm, h=5cm, MA=l/h, MA=17cm/5cm

PETTING A DOG

At the end of the ramp the balls drop into a screw.

MA for the screw is 0.4 circumference=1.6ft pitch=4 MA= circumference/pitch, MA= 1.6ft/4ft

PETTING A DOG

Balls drop out of screw and are separated by a wedge.

MA for a wedge is 0.4 h=4cm, b=10.5cm, MA=h/b MA=4cm/10.5cm

PETTING A DOG

Wedge leaves 1 ball to travel down a ramp.

The MA for the 3rd inclined plane is 2.7 l= 32cm, h=12cm MA= l/h MA=32cm/12cm

PETTING A DOG

At the end of the ramp is a pulley system The MA of the pulley system is 1

Number of support strings=1

PETTING A DOG

Ball is released from pulley system and hits a domino

This pushes the yo-yo MA for wheel and axle is 0.2 axle radius= 0.5cm wheel radius= 3cm MA=axle radius/wheel radius MA=0.5cm/3cm

PETTING A DOG

Yo-yo releases the piece of wood holding up the hand that will pet the dog.

PETTING A DOG

Total simple machines Levers= dominoes Pulley System = cup pulley system Wedge = separator Inclined Planes = 3 ramps Screw = spiral ball travels down Wheel and axle = yo-yo