Transcript Geared Mousetrap Car

Warm Up Activity
1. Pick up a poker chip from the teacher.
2. 3 chips per team:
• 1 white, 1 blue, and 1 red per team.
3. Sit with your team members.
Warm Up Activity
4. Open your engineering notebook and title
the page: Preliminary Challenge #21:
Geared Mousetrap Car
5. Begin discussions about:
 The Design of the Traditional Mousetrap Car
 How to Use Gears to Transfer Power
 The Use of a Lever Arm to Create a Pulling
Force
Share Out
• What ideas did your group discuss?
• How will your group use gears?
• How does a mousetrap car work?
Preliminary Challenge #21
Mousetrap Powered Gear Car
Science, Technology,
Engineering, and Math
Concepts Review
Momentum
• The quantity of motion of a moving
body, measured as a product of its
mass and velocity.
• Momentum = mass x velocity
Acceleration
• The rate of change of velocity of an
object.
• Acceleration = (final velocity - initial
velocity) ÷ time
Speed
• The rate at which someone or
something is able to move or
operate.
• Speed = distance ÷ time
Force
• A force is a push or pull upon an
object resulting from the object's
interaction with another object.
• Force = mass x acceleration
Weight
• A body's relative mass or the
quantity of matter contained by it,
giving rise to a downward force; the
heaviness of a person or thing.
• Weight = mass x gravity (9.8 m/s2 )
Work
• The product of a force applied, and
the distance through which that
force acts.
• Work = Force x distance
Power
• The amount of energy put out or
produced in a given amount of time.
• Power = Work ÷ time
Friction
• The force resisting the relative motion of solid
surfaces, fluid layers, and material elements
sliding against each other.
Look at the next slide
and think of what it
reminds you of…
Gears
Gearing Mousetrap Cars
• Gearing is what determines how far and how
fast a mousetrap racer will travel.
• Gearing is how you control the acceleration,
the pulling force, the torque, and the travel
distance of your mousetrap vehicle.
• With mousetrap powered vehicles the gearing
is always the combination of the lever arm
length and the axle to wheel ratio.
Gearing Mousetrap Cars
• As the string is pulled from the drive axle the
mousetrap car is propelled by the turning of the
drive wheels.
• It is the combination of the size of the wheels and
the amount of string that is pulled from the drive
axle that will determine how far the mousetrap
vehicle is pulled by the force of the mouse trap.
• In most long-distance contest the objective is to
propel a mousetrap car the longest possible
linear distance. In this example the gearing will be
set-up in such a way as to extend the mouse
trap's energy over the longest possible distance.
Gearing Mousetrap Cars
• The length of the mouse trap's lever arm and
the drive axle to wheel ratio will all determine
the gearing and the performance of your
mousetrap vehicle.
• Gearing is controlled by the following:
 the length of the lever arm
 the size of the drive wheel(s)
 the size of the drive axle
Engineering Design
Process
Engineering Design Process (1-7)
1.
2.
3.
4.
5.
6.
7.
Define The Problem
Brainstorm Possible Solutions
Research Ideas/Explore Possibilities
Specify Constraints And Identify Criteria
Consider Alternative Solutions
Select An Approach
Develop Written Design Proposal
Building Stage
Engineering Design Process (8-12)
8. Make Model/Prototype
9. Test And Evaluate
10.Refine/Improve
11.Create/Make Product
12.Communicate Results
Preliminary Challenge #21
Design Problem:
Using the 12 step Engineering Process,
design a vehicle that is powered by a gears
and a mousetrap. The vehicle must carry
one pound a minimum horizontal distance
of twenty-five feet, or travel up a 30⁰
incline a minimum of ten feet.
The vehicle must carry
one pound a minimum
horizontal distance of
twenty-five feet
or
25 Feet
The vehicle must
travel up a 30⁰ incline
plane a minimum
distance of ten feet
Preliminary Challenge #21
Using the 12 step Engineering Process, design a vehicle
that is powered by a gears and a mousetrap.
Your choice of materials are:
– Wheels
– Cardboard
– Hot Glue
– Wood Dowel (1)
– Gears (4)
– Mousetrap (1)
– Straws (3)
– Paper
– Wood/Metal Strips
http://www.docfizzix.com/topics/designbasics/MouseTrap-Cars/mousetrapvehicles-gearing.shtml
Preliminary Challenge #21
Using the 12 step Engineering Process, design a vehicle that is
powered by a gears and a mousetrap. The vehicle must carry one
pound a minimum horizontal distance of twenty-five feet, or travel up
a 30⁰ incline a minimum of ten feet.
• Steps 1 through 7 must be
completed in your
engineering notebook and
checked by teacher.
• After steps 1 through 7 have
been completed, the
students will be given
materials to complete the
project.
Your choice of materials are:
– Wheels
– Cardboard
– Hot Glue
– Wood Dowel (1)
– Gears (4)
– Mousetrap (1)
– Straws (3)
– Paper
– Wood/Metal Strips
Preliminary Challenge #21