Content Area: Physics (11-12)
Topic: Kinematics
Sub-Topic: Linear Velocity and Acceleration
Computer requirements: Vensim or STELLATM, IP physics,
Excel or Internet access
Prior content covered: None
Estimated time for computer portion of lesson:
60 min
Essential Questions or Ideas to address:
- How are velocity and acceleration different?
- How are velocity and acceleration related?
- How do we interpret graphs of motion in terms of velocity
and acceleration?
The lesson (90-min block): In the first half-
hour, students build a basic constant velocity model and explore the
effects of changing the initial position or the velocity on the
position-time and velocity - time graphs produced. This model is
a basic introduction to Vensim or STELLATM icons and the graph output. The
model can also be used to model data collected in class.
In the second half-hour, students add acceleration
to the model and again explore the effects of changing variables on the
graphs produced. This basic acceleration model is at the heart of many
future models. For more details, see the Simple Kinematics Activity Packet.
Common misconceptions addressed:
- Objects at rest cannot be accelerating.
- Velocity and acceleration must be in the same direction.
- Same position means same speed
- Velocity must be positive
Evaluation of lesson effectiveness: The
primary purpose of this lesson is to introduce students to Vensim, STELLA
TM or
another modeling environment while the content is fairly simple.
However, if the activities and follow-up questions are crafted
carefully enough, many student misconceptions can be addressed early
on. In addition, students can be exposed to a variety of graphs
in a short time and begin to build their graph interpretation
skills.
Alternate presentation: It is easy
enough to build one or more Excel worksheets that allow students to
explore the variables and their effect on various graphs. All
that is lost is the visible relationship between those variables
which can be inferred from the Vensim/STELLATM model. This relationship
could be emphasized through a concept map.
It is also useful to explore velocity and
acceleration using an Interactive Physics program or web-based
applet. In this case, students can actually observe the particles
moving and if a trace function is used, it help students distinguish
position from velocity and to readily see the effects of velocity and
acceleration on movement. An interactive physics model can be found at:
http://www.interactivephysics.com
Math topics: Linear and quadratic equations,
graph interpretation for those equations
Standards:
MSDE (from the website as of 9/05):
| Physics/Core Learning Goals |
| Science Indicator 5.1.2 |
|
The student will use algebraic and geometric concepts to
describe an object's motion.
Assessment Limits
direction, position, distance/displacement,
speed/velocity, motion with a constant acceleration, one and two
dimensional motion, frames of reference
|
Goal 5 Concepts Of Physics
The student will demonstrate the ability to use scientific skills and
processes (Core Learning Goal 1) to explain and predict the outcome of
certain interactions which occur between matter and energy.
Expectation 5.1
The student will know and apply the laws of mechanics to explain the
behavior of the physical world.
|
The
standards do not directly address kinematics, but an understanding of
motion is necessary before students can address the standards as they
appear here.
National Science Standards:
Physical Science: Motion and Forces:
Objects change their motion only when a net force is applied. Laws of
motion are used to calculate precisely the effects of forces on the
motion of objects. The magnitude of the change in motion can be
calculated using the relationship F = ma, which is independent of the
nature of the force. Whenever one object exerts a force on
another, a force equal in magnitude and opposite in direction is
exerted on the first object.
AAAS Benchmarks:
The Physical Setting: Forces of
Nature:
- The change in motion of an object is is proportional to
the applied force and inversely proportional to the mass.
- All motion is relative to whatever frame of reference is
chosen, for there is no motionless frame from which to judge all motion.