1. Matt Elder Jessa Meyers Ryan Lewis Michael Love
Lazy
Brusher!
Matt Elder
Jessa Meyers
Ryan Lewis
Michael Love

2. Overview
Our device utilizes both conservation of energy and conservation of momentum to achieve a final task of squirting toothpaste onto a toothbrush.
Energy transfers in the system include
balls rolling down inclined planes and free
falls.
Conservation of momentum is
illustrated by the impact of a smaller
and larger ball and by a tennis ball
knocking over a hammer.

3. Our Group

4. Conservation Of Energy
Used to calculate speed (initial or final) of an object or the height (initial or final) of an object
KEo+PEo+Win=KE+PE+Eloss
½ mvo2+mgho= ½ mv2+mgh

5. Conservation Of Energy
marble rolling down first incline
tennis ball rolling down second incline
marble falling and rolling down second incline toward the toothbrush

6. Conservation Of Momentum
Used to determine the velocity of an object upon collision with another object
m1v1+m2v2=m1v1’+m2v2’
Coefficient of Restitution calculates
the velocity with which the object
bounces back
e= - (v1’-v2’)
(v1-v2)

7. Conservation Of Momentum
marble hitting the tennis ball to start the tennis ball moving
tennis ball striking
hammer which will in
turn hit the toothpaste
marble colliding with toothbrush to nudge it into place

8. ...None other than
Lazy Dog
Who is the
Lazy Brusher?