| Activity
Name |
Students
do this |
Challenge
or prediction |
Concept/Skill |
Links
to detailed description |
| Kinematics, Newton's Laws in one dimension. |
| Constant acceleration:
Rolling Friction 1 |
Collect and analyze
displacement data using different sensors.
Draw free body diagrams. |
Calculate friction
force.
What is the friction
force introduced by the various kinds and configurations of sensors?
What is exerting
this force? On what?
Draw a free body
diagram. |
Identifying
external forces. Distinguishing between external and internal forces.
Distinguishing
between static and kinetic friction in rolling problems. |
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| Constant acceleration:
Rolling Friction 2 |
Collect and analyze
displacement data over a slightly sloping floor. |
How can you distinguish
between sloping floor and friction?
Learn to use Robolab
Investigator to document your project and analyze data. |
Using free
body diagrams.
Solving problems
with two kinds of forces. |
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| Constant acceleration:
Rolling Friction 3 |
Collect and analyze
displacement data using different loads.
Draw free body diagrams. |
How does the friction
force depend on Normal force?
How does friction
force depend on velocity? |
|
To
be added soon. |
| Spring Force Gauge |
Build and calibrate
a force gauge, using Legos and a spring with a rotation sensor. |
Use a spring and
rotation sensor to make a force gauge.
How repeatable is
your instrument?
What is the resolution?
How can you make it finer? What is lost when resolution is improved? |
Spring force:
Hooke's Law.
Design and use of
an instrument. Tradeoffs between sensitivity and repeatability.
Dealing with imperfections
- hysteresis.
Calibration. |
 Examples
and details |
| Static and Kinetic
Friction |
Use the force gauge
that you have built to measure frictional force as an object is pulled and
begins to slide. |
How does friction
force depend on surface area?
How does friction
force depend on load? |
Static and sliding
friction. Analysis of graph.
Normal force, coefficient
of friction.
|
 This
is a simple application of the force gauge. Click
here for details |
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| Conservation
of Energy |
| Rolling Energy Analysis |
Use rotation sensor
to collect displacement data for a cart as it rolls to a stop.
|
What is the frictional
force acting on a rolling cart?
Calculate Frictional
force in at least two ways. |
Force due to friction
Work done by friction
Conservation of energy |
Examples
and details. |
| Ramp |
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This
activity uses the rotation sensor to collect data used to analyze the
motion of a cart rolling down a ramp.
Click
here to see ROBOLAB project results. |
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| Rotational
Dynamics |
| Activity Name |
Students do
this |
Challenge
or prediction |
Concept/Skill |
Links to detailed
description |
Measuring moments
of inertia
Frictional torque
of axle and bearing.
|
Use LEGO
blocks as masses to apply torque to a wheel and cause angular acceleration.
Use light sensor
to acquire data on wheel position.
|
Calculate
acceleration.
Use a free body diagram
to show how to calculate torque.
Apply Newtons second
law to put data into a form that gives the moment of inertia of the wheel,
and the frictional torque in the axle. |
Newton's 2nd law
in rotational and linear form.
Deriving a result
from a graph of calculated data points. |
Click
here for details. |
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| Conservation of angular
momentum: precession. |
Use a high speed,
non-geared Lego motor to spin some tires very rapidly. Suspend the RCX,
motor and wheel so that the whole arrangement is allowed to tilt as shown,
pivoting around the end of the strings that hold it up. |
As you rotate the assembly
about its vertical axis, what happens?
What if the motor
is spinning the other way?
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Physical Pendulum
|
Use a given set
of bricks to make pendulums with different periods.
Measure the period. |
Level 1: Build
the slowest and fastest possible pendulums from a given set of bricks.
Level 2: Explain
what influences the period of the pendulums.
Level 3: With an
axle and a several identical bricks, build a rod-shaped pendulum and measure
its period as the pivot point is moved relative to the center of mass.
Level 4: Plot the
data and model it mathematically. Develop a strategy to make fast pendulums
with a given mass.
|
Measuring pendulum
period.
Effect on period
as mass is distributed differently.
Gravitational force
acting on center of mass.
Plotting data.
Gravitational torque,
moment of inertia, parallel axis, pendulum equation.
Analyzing data, and
comparing to a mathematical model. |
Examples
and details. |
| Optics |
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| Object-image and magnification |
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 LEGO's
make a very nice optical bench. You just need to come up with a way to hold
your lenses. I will add some ideas to this site soon. |
| Finding the focal
length using a laser pointer |
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| Telescope and a microscope |
Build a telescope.
Build a microscope.
Measure magnification. |
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| Diffraction grating |
Use a laser pointer
to calculate the spacing of tracks on a CD.
Verify using optical
microscope. |
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| Grating Spectrometer |
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Not yet realized! |
| Heat and Energy |
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