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Utah Science

Curriculum Consortium

Tyson Grover 

tgrover@dsdmail.net

Annette Nielson

afonnesbeck@dsdmail.net

3.3 Strand

Forces act on objects and have both a strength and a direction. An object at rest typically has multiple forces acting on it, but they are balanced, resulting in a zero net force on the object. Forces that are unbalanced can cause changes in an object’s speed or direction of motion. The patterns of an object’s motion in various situations can be observed, measured, and used to predict future motion. Forces are exerted when objects come in contact with each other; however, some forces can act on objects that are not in contact. The gravitational force of Earth, acting on an object near Earth’s surface, pulls that object toward the planet’s center. Electric and magnetic forces between a pair of objects can act at a distance. The strength of these non-contact forces depends on the properties of the objects and the distance between the objects.
STORYLINE: 3.3.1: Forces & Motion
 

Standard(s) 3.3.1: Plan and carry out investigations that provide evidence of the effects of balanced and unbalanced forces on the motion of an object. Emphasize investigations where only one variable is tested at a time. Examples could include an unbalanced force on one side of a ball causing it to move and balanced forces pushing on a box from both sides producing no movement. (PS2.A, PS2.B)

Practices

Planning and Carrying Out Investigations to answer questions or test solutions to problems in 3–5 builds on K–2 experiences and progresses to include investigations that control variables and provide evidence to support explanations or design solutions. 

  • Make observations and/or measurements to produce data to serve as the basis for evidence for an explanation of a phenomenon.

Disciplinary Core Ideas

PS2.A: Forces and Motion 

Each force acts on one particular object and has both strength and a direction. An object at rest typically has multiple forces acting on it, but they add to give zero net force on the object. Forces that do not sum to zero can cause changes in the object’s speed or direction of motion. (Boundary: Qualitative and conceptual, but not quantitative addition of forces are used at this level.) 

PS2.B: Types of Interactions 

Objects in contact exert forces on each other.

Cross Cutting Concepts

Cause and Effect relationships are routinely identified, tested, and used to explain change.

Storyline Narrative

This storyline focuses heavily on cause and effect relationships.  Students begin the storyline by examining engaging phenomena that show forces acting on different objects. Students formulate ideas and questions about why these particular phenomena take place and begin to build background knowledge about forces Students look for cause and effect relationships as they learn about forces.  They explore types of interactions involving forces (PS2.B): contact and non-contact.  Students again identify cause and effect relationships and learn to identify whether a force is a contact or a non-contact force, then move on to build understanding of net forces.  Students find cause and effect relationships in examples such as a game of tug-of-war, and relate them to balanced and unbalanced forces.  Students understand at this point that a net force is when the sum of all forces on an object equals zero.  Once all of this understanding has been built, students use the knowledge they have gathered to plan and conduct an investigation collaboratively that provides evidence of the effects of balanced and unbalanced forces on the motion of an object.

Phenomena Statement

When a hockey player hits a puck, it moves across the ice--This demonstrates forces acting on a particular object with strength and direction.  The phenomenon shows that forces that do not sum to zero can cause changes in the object’s speed or direction of motion (PS2.A) and ties in the cross-cutting concept of cause and effect.

STORYLINE: 3.3.2-3.3.3: Predicting Motion
 

Standard(s) 3.3.2: Analyze and interpret data from observations and measurements of an object’s motion to identify patterns in its motion that can be used to predict future motion. Examples of motion with a predictable pattern could include a child swinging on a swing or a ball rolling down a ramp. (PS2.A, PS2.C)


Standard(s) 3.3.3: Construct an explanation that the gravitational force exerted by Earth causes objects to be directed downward, toward the center of the spherical Earth. Emphasize that “downward” is a local description depending on one’s position on Earth. (PS2.B)

Practices

Analyzing and Interpreting Data Analyzing data in 3–5 builds on K–2 experiences and progresses to introducing quantitative approaches to collecting data and conducting multiple trials of qualitative observations. When possible and feasible, digital tools should be used. 

Analyze and interpret data to make sense of phenomena using logical reasoning.

Constructing Explanations and Designing Solutions in 3–5 builds on K–2 experiences and progresses to the use of evidence in constructing explanations that specify variables that describe and predict phenomena and in designing multiple solutions to design problems. 

∙ Generate and compare multiple solutions to a problem based on how well they meet the criteria and constraints of the design solution.

Disciplinary Core Ideas

PS2.A: Forces and Motion 

The patterns of an object’s motion in various situations can be observed and measured; when that past motion exhibits a regular pattern, future motion can be predicted from it. (Boundary: Technical terms, such as magnitude, velocity, momentum, and vector quantity, are not introduced at this level, but the concept that some quantities need both size and direction to be described is developed.)

 

PS2.B: Types of Interactions 

The gravitational force of Earth acting on an object near Earth’s surface pulls that object toward the planet’s center.

Cross Cutting Concepts

Patterns can be used as evidence to support an explanation. 


Cause and Effect relationships are routinely identified, tested, and used to explain change.

Phenomena Statement

When I play basketball I can dribble and pass the ball where and how I want.

STORYLINE: 3.3.4: Non-contact Forces
 

Standard(s) 3.3.4: Ask questions to plan and carry out an investigation to determine cause and effect relationships of electric or magnetic interactions between two objects not in contact with each other. Emphasize how static electricity and magnets can cause objects to move without touching. Examples could include the force an electrically charged balloon has on hair, how magnet orientation affects the direction of a force, or how distance between objects affects the strength of a force. Electrical charges and magnetic fields will be taught in Grades 6 through 8. (PS2.B)

Practices

Asking Questions and Defining Problems in grades 3–5 builds on grades K–2 experiences and progresses to specifying qualitative relationships.

  • Ask questions that can be investigated based on patterns such as cause and effect relationships.

Planning and Carrying Out Investigations to answer questions or test solutions to problems in 3–5 builds on K–2 experiences and progresses to include investigations that control variables and provide evidence to support explanations or design solutions. 

  • Make observations and/or measurements to produce data to serve as the basis for evidence for an explanation of a phenomenon.

Disciplinary Core Ideas

PS2.B: Types of Interactions 

Electric, and magnetic forces between a pair of objects do not require that the objects be in contact. The sizes of the forces in each situation depend on the properties of the objects and their distances apart and, for forces between two magnets, on their orientation relative to each other.

Cross Cutting Concepts

Cause and Effect relationships are routinely identified, tested, and used to explain change.

Phenomena Statement

Static electricity can cause objects to move without touching.

Magnets can cause objects to move without touching.

Storyline Narrative

Students explore phenomena that have to do with electricity and magnetism.  They tie into the knowledge they gained previously in the bundle about non-contact forces, and use that knowledge to make observations about cause and effect relationships, as well as to formulate questions regarding electric and magnetic interactions.  Students plan and conduct investigations  to learn about what factors can affect the sizes and directions of forces in both magnetic and electric interactions.  This piece of the bundle wraps up with students formulating questions about electric and magnetic interactions form the real word and identifying the cause and effect relationships they see.

STORYLINE: 3.3.5: Magnetic Devices

Standard(s) 3.3.5: Design a solution to a problem in which a device functions by using scientific ideas about magnets. Define the problem, identify criteria and constraints, develop possible solutions using models, analyze data from testing solutions, and propose modifications for optimizing a solution. Examples could include a latch or lock used to keep a door shut or a device to keep two moving objects from touching each other. (PS2.B, ETS1.A, ETS1.B, ETS1.C)

Practices

Constructing Explanations and Designing Solutions in 3–5 builds on K–2 experiences and progresses to the use of evidence in constructing explanations that specify variables that describe and predict phenomena and in designing multiple solutions to design problems. 

∙ Generate and compare multiple solutions to a problem based on how well they meet the criteria and constraints of the design solution.

Disciplinary Core Ideas

PS2.B: Types of Interactions 

Electric, and magnetic forces between a pair of objects do not require that the objects be in contact. The sizes of the forces in each situation depend on the properties of the objects and their distances apart and, for forces between two magnets, on their orientation relative to each other.

Cross Cutting Concepts

Structure and Function: A system can be described in terms of its components and their interactions.

Storyline Narrative

 In this storyline, students use the knowledge they have constructed about magnets to define a problem in their classroom or home that can be solved with magnets, then they design a solution. Students base their solution on the structure and function of magnets.

Phenomena Statement

Magnets can be used to solve problems.