Unit Overview

Students investigate how forces affect motion discovering Newton's Laws govern all movement. Through solving mysteriously moving supermarket items or testing levitating car models with magnets, conducting three investigations with marbles and ramps testing each law collecting photo and video evidence, and engineering shopping cart crash protectors using force principles safeguarding eggs during collisions, students learn predicting motion outcomes in everyday situations.

• Next Generation Science Standards

  MS-PS2-1

  Apply Newton’s Third Law to design a solution to a problem involving the motion of two colliding objects.* [Clarification Statement: Examples of practical problems could include the impact of collisions between two cars, between a car and stationary objects, and between a meteor and a space vehicle.] [Assessment Boundary: Assessment is limited to vertical or horizontal interactions in one dimension.]

  MS-PS2-2

  Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object. [Clarification Statement: Emphasis is on balanced (Newton’s First Law) and unbalanced forces in a system, qualitative comparisons of forces, mass and changes in motion (Newton’s Second Law), frame of reference, and specification of units.] [Assessment Boundary: Assessment is limited to forces and changes in motion in one dimension in an inertial reference frame and to change in one variable at a time. Assessment does not include the use of trigonometry.]

  MS-PS2-4

  Construct and present arguments using evidence to support the claim that gravitational interactions are attractive and depend on the masses of interacting objects. [Clarification Statement: Examples of evidence for arguments could include data generated from simulations or digital tools; and charts displaying mass, strength of interaction, distance from the Sun, and orbital periods of objects within the solar system.] [Assessment Boundary: Assessment does not include Newton’s Law of Gravitation or Kepler’s Laws.]

  MS-PS2-5

  Conduct an investigation and evaluate the experimental design to provide evidence that fields exist between objects exerting forces on each other even though the objects are not in contact. [Clarification Statement: Examples of this phenomenon could include the interactions of magnets, electrically charged strips of tape, and electrically charged pith balls. Examples of investigations could include first hand experiences or simulations.] [Assessment Boundary: Assessment is limited to electric and magnetic fields, and limited to qualitative evidence for the existence of fields.]

• Inquiry Scale
  • Each lesson in the unit has an Inquiry Scale that provides directions on how to implement the lesson at the level that works best for you and your students.
  • “Level 1” is the most teacher-driven, and recommended for students in 4th-5th grades. “Level 4” is the most student-driven, and recommended for students in 7th-8th grades.
  • For differentiation within the same grade or class, use different inquiry levels for different groups of students who may require additional support or an extra challenge.
• Common Misconceptions
  • Learners often think of friction as its own separate concept rather than an example of a force acting on objects in motion. During the animation, emphasize this.
  • Learners initially have trouble understanding that objects in motion will stay in motion unless a force acts upon it because gravity and friction are not visual phenomena that they can see, but they can feel. In this sledding example, gravity is pulling the sled down the hill, and the snow applies very little friction. What would it be like sledding on grass?
  • Learners often think of the word “force” as something deliberate, in accordance with their life experience, so emphasize in reference to the animation that even stationary objects that are holding things up are also applying a force.
  • Students may think that the outcome of every collision is the same. Emphasize to students that the strength of a collision depends on the mass, direction and speed of objects that collide.
• Vocabulary
  • • Motion
    • Friction
    • Gravity
    • Applied Force
• Content Expert
  • Hans C. von Baeyer
    Chancellor Professor of Physics, Emeritus College of William and Mary