Physical Science
Thursday-Friday 11-8
Old Work
New work
Hand in homework
• Pencil Sharpener Rube Analysis
• Handout on Equations and energy review
New Homework
• P407 problems 1-3 on efficiency
Eff = Wo
Wi
x 100
Remember, W = F x d
Also for homework
• P408 1-9
Conservation of energy
• Open or closed system
• What does it mean
Conservation of energy
• Closed system – energy remains constant
in system over time
• Open system – energy flows in/out of the
system
• Law– in a closed system, energy can not
be created or destroyed, only
transferred/transformed.
Roller Coaster
Roller Coaster Building
• Workbook
• Answer questions on page 10
Potential energy = GPE
Read Pages 11,12 on energy and roller
coasters
Question?
• Some company on the scale of Disney or
Universal studios is planning to open a top
rank amusement park in Delaware.
• They are asking for design proposals for
the wildest, coolest ride ever created.
• That is where you come in to the picture
Roller Coaster Design
• Maximum length of prepared track is 24 ft
• The ball must end exactly 35cm off the ground
• Track must have at least 2 hills (at least 55 cm
of relief) in the run
• Track must touch the floor at least once
• Track must have at least one unusual feature
(Curve, loop, jump…)
• One hill must be high enough for the marble to
just barely pass over the top.
• The marble must come to a rest in 30 cm
because of increased friction
The sections of the project
• Performance stage
• Design and Analysis stage
Materials
• Track is to be made out of pipe insulation
• The ball will be steel, glass or wood
• The track will be primarily connected to the wall
by duct tape (though other supports can be
added
• The track will have to be put up and taken down
every class period (special sections can be built
and stored in the back of my room)
Performance
• Can you keep a marble along the track
from start to finish while accomplishing its
goals?
• Can you do the task twice with the same
set-up?
Design and Analysis
• Can you record the height of your roller coaster
at each place where it changes direction, and
including start and end points?
• Can you record the distance between each
vertical measurement
• Can you sketch a scale model of your roller
coaster?
Analysis
• Can you calculate the GPE at any point along the roller
coaster?
• Can you use the concept of energy conservation to
determine KE and TE at different points along the course
• Can you relate the laws of motion what will be
experienced by the riders of your roller coaster?
• Can you determine the amount of work and the power
output done to lift the car to the top of the roller coaster?
Honors
• Determine the scale of the real roller coaster you
would create.
• Estimate the mass of the car and passengers
• Determine KE, GPE and TE at important
sections of the track
• Create a free body diagram and determine the
force at important sections of the track
Pick Groups
• Pick your groups for the project
• 2-4 members
• Everybody in class must be included
In class Assignment
• Investigate Speed, Height and Energy
• Work through pages 20-25
• Before you answer the questions on pg
25, read the article on page 26