Motion Teacher Guide

Unit

Motion

Subject

Physical Science

Grade Level

MS

Activity Names

Making Waves

Seeing Motion

Being Prepared

Students should work with a partner (this can be done with groups of 3, but it works easiest with 2). You also need to make sure you have adequate space so that the students can stay out of range of each other's motion detectors. This space also needs to be cleared of other objects within the range of the detectors or the detectors will give false readings.

You will need:

• Motion detectors
• Tape (masking or painters that can mark the floor and be removed)
• Flat object (notebook, binder, box lid, etc.)

Getting Started

If you haven't used an activity with graphs before you might want to demonstrate how to use the graphs or have the help section available for the students (insert links to help pdf and video here)

Suggested Timeline

Making Waves

If you have groups of 2 and probes for each group, two 45-50 minute periods or 1 block period to complete this.

Seeing Motion

If you have groups of 2 and probes for each group, two 45-50 minute periods or 1 block period to complete this.

If you have to make larger groups or have less probes, this will take longer. Either activity can be broken up and does not have to be completed in one sitting.

Thinking about the Discovery Questions

This unit is motivated by the discovery questions:

• How can motions be repeated?
• How can you describe and illustrate motion?

These activities show the starting concepts of motion and how it appears on a graph. The students will observe how changing the direction of motion and the speed of motion changes how it appears on a distance/time graph. These activities will show students the equation speed = distance/time.

Misconceptions

A common misconception students will have is that a line "going up" means faster and a line "going down" means slower.

Students will commonly think that removing the force from a moving object will cause it to stop. They will also think that motion requires a force, even constant motion. Try to point out on the graphs where the forces are applied (at any change in the slope of the line)

Learning Objectives

• NGSS
  • Performance Expectations
    • MS-PS3-2. Develop a model to describe that when the arrangement of objects interacting at a distance changes, different amounts of potential energy are stored in the system.
  • Disciplinary Core Ideas
    • MS-PS3: Energy
      • PS3.A: Definitions of Energy
        • A system of objects may also contain stored (potential) energy, depending on their relative positions. (MS-PS3-2)
      • PS3.C: Relationship Between Energy and Forces
        • When two objects interact, each one exerts a force on the other that can cause energy to be transferred to or from the object. (MS-PS3-2)
  • Practices
    • Developing and using models
      • Develop and/or use a model to predict and/or describe phenomena.
      • Develop a model to describe unobservable mechanisms.
  • Crosscutting Concepts
    • Systems and system models
      • Students can understand that systems may interact with other systems; they may have sub-systems and be a part of larger complex systems. They can use models to represent systems and their interactions — such as inputs, processes and outputs — and energy, matter, and information flows within systems. They can also learn that models are limited in that they only represent certain aspects of the system under study.
• NSES
  • NSES Physical Science – Motion and Forces
    • The motion of an object can be described by its position, direction of motion, and speed. That motion can be measured and represented on a graph.

Discussion: Setting the Stage

Making Waves

• What is motion?

  The change in position related to a stationary object during an amount of time.

• In what ways can motion be repeated?

  Clock pendulum, a child on a swing, a person pacing, etc.

Seeing Motion

• Is it possible to determine how far away a person or object is from you without having a tape measure or meter stick?

  Yes, if you have a way to measure their speed and and the amount of time it takes them.

Discussion: Formative Questions

Making Waves & Seeing Motion

• What makes the line go up?

  Moving away from the sensor

• What makes the line go down?

  Moving toward the sensor

• What makes the line stay flat?

  Not moving

• What changes the slope of the line?

  The speed at which the object (person) moves

Discussion: Wrapping Up

• Why did you see the changes that you did, what caused the line to move?

  The line moved up and down depending on if they moved closer or farther away from the sensor. The slope increased and decreased if they moved faster or slower. The curves and points depended on how fast they change direction.

• What caused you to change speed or direction (other than making the decision to do so)?

  Answers will vary, but the idea is to guide the students into a discussion about how they had to apply a force to change their direction and speed.

Additional Background

This is a good introduction to forces and motion. It gets students thinking about how motion graphs, but doesn't really address the how of motion. The wrap-up discussion is where you get into the concept that a force must be applied to change their motion whether it is changing direction or changing speed.

Analysis

Making Waves

1. Do you notice any differences or similarities in the direction or speed of the box when making curved, square or triangular waves?

   All require forward and backward motion; curved is a gradual change in direction; square standing in place, quickly jumping forward/back, standing in place; triangular has a quick change in direction, but constant motion.

2. Which type of wave was the hardest to reproduce? Why?

   Answer will vary based on student opinion.

3. Can you identify an object in the real world that experiences each type of these motions?

   Answers will vary, there are many examples.

Seeing Motion

1. How did the actual motion compare to your predictions? Explain any differences.

   Answer will vary.

2. How are changes in speed and direction represented on the graphs?

   Change in speed is represented by a change in slope, change in direction is represented by changing the slope from positive to negative and back again

3. What did you learn about motion in relationship to the movement of your body?

   Motion changes when the student makes an effort (applies a force): steep line = faster, horizontal line = stopped, up = away, down = toward.

Further Investigation

Have students design additional investigations using everyday objects (e.g., motorized cars, pull toys, etc.) to futher investigate the relationships between an object's position, velocity, and acceleration by using graphs.