Projectile Motion Lesson

Content Area: Physics (11-12)
Topic: Two-Dimensional Motion
Sub-Topic: Projectiles

Computer requirements: Vensim, STELLA, Interactive Physics or Excel
Prior content covered: Linear velocity and acceleration, free fall
Estimated time for computer portion of lesson: 30 - 45 min

Essential Questions or Ideas to address:

• Independent nature of the x and y components of projectile motion
• How do the horizontal and vertical velocity vectors change as the object moves through its path?
• In the case of no horizontal forces, what is the direction of the acceleration acting on the projectile?

The lesson (90-min block): Students build or use a Vensim or STELLATM model, Excel spreadsheet or an Interactive Physics simulation to investigate projectile motion. The structure of the Projectile Motion systems model illustrates the independent nature of the vector quantities. On the other hand, Interactive Physics allows the students to see the vectors as the object progresses through its trajectory. Students can use any of the models to determine the best angle for maximum distance.

For an example of a Vensim/STELLATM model and companion activities see the Projectile Motion Activity Packet.

• The acceleration follows the flight path.
• The vertical motion "affects" the horizontal motion and vice versa.

Evaluation of lesson effectiveness: While building a projectile model can be time consuming, having the students use a pre-built model is valuable.  Student understanding of the nature of the vectors involved and their chance to manipulate the variables in meaningful ways leads to deeper conceptual understanding of projectile motion.

Alternate presentation:  There are many applets available on the web. For web applets which show the vectors, look under two-dimensional motion at The Physics Classroom.
Other web applets can be found at Projectile Motion WebSim or http://www.walter-fendt.de/ph11e/projectile.htm

Math topics: Linear and quadratic equations, graph interpretation for those equations, vectors and vector addition

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.

 Home | Contact | Site Map | Search