# 3-PS2-1 Motion and Stability: Forces and Interactions

3-PS2-1   Motion and Stability: Forces and Interactions

Students who demonstrate understanding can:

3-PS2-1. Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object. [Clarification Statement: Examples could include an unbalanced force on one side of a ball can make it start moving; and, balanced forces pushing on a box from both sides will not produce any motion at all.] [Assessment Boundary: Assessment is limited to one variable at a time: number, size, or direction of forces. Assessment does not include quantitative force size, only qualitative and relative. Assessment is limited to gravity being addressed as a force that pulls objects down.]
The performance expectation above was developed using the following elements from the NRC document A Framework for K-12 Science Education:

## Science and Engineering Practices

### Planning and Carrying Out Investigations

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.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

### Scientific Investigations Use a Variety of Methods

• Science investigations use a variety of methods, tools, and techniques.

## 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.)

## Crosscutting Concepts

### Cause and Effect

Connections to other DCIs in third grade: N/A

Articulation of DCIs across grade-levels:

Common Core State Standards Connections:

 RI.3.1 ELA/Literacy - Ask and answer questions to demonstrate understanding of a text, referring explicitly to the text as the basis for the answers. (3-PS2-1) Conduct short research projects that build knowledge about a topic. (3-PS2-1) Recall information from experiences or gather information from print and digital sources; take brief notes on sources and sort evidence into provided categories. (3-PS2-1) Mathematics - Reason abstractly and quantitatively. (3-PS2-1) Use appropriate tools strategically. (3-PS2-1) Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l). Add, subtract, multiply, or divide to solve one-step word problems involving masses or volumes that are given in the same units, e.g., by using drawings (such as a beaker with a measurement scale) to represent the problem. (3-PS2-1)

3-PS2-1   Motion and Stability: Forces and Interactions

Students who demonstrate understanding can:

3-PS2-1. Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object. [Clarification Statement: Examples could include an unbalanced force on one side of a ball can make it start moving; and, balanced forces pushing on a box from both sides will not produce any motion at all.] [Assessment Boundary: Assessment is limited to one variable at a time: number, size, or direction of forces. Assessment does not include quantitative force size, only qualitative and relative. Assessment is limited to gravity being addressed as a force that pulls objects down.]
The performance expectation above was developed using the following elements from the NRC document A Framework for K-12 Science Education:

## Science and Engineering Practices

### Planning and Carrying Out Investigations

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.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

### Scientific Investigations Use a Variety of Methods

• Science investigations use a variety of methods, tools, and techniques.

## 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.)

## Crosscutting Concepts

### Cause and Effect

Connections to other DCIs in third grade: N/A

Articulation of DCIs across grade-levels:

Common Core State Standards Connections:

 RI.3.1 ELA/Literacy - Ask and answer questions to demonstrate understanding of a text, referring explicitly to the text as the basis for the answers. (3-PS2-1) Conduct short research projects that build knowledge about a topic. (3-PS2-1) Recall information from experiences or gather information from print and digital sources; take brief notes on sources and sort evidence into provided categories. (3-PS2-1) Mathematics - Reason abstractly and quantitatively. (3-PS2-1) Use appropriate tools strategically. (3-PS2-1) Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l). Add, subtract, multiply, or divide to solve one-step word problems involving masses or volumes that are given in the same units, e.g., by using drawings (such as a beaker with a measurement scale) to represent the problem. (3-PS2-1)

3-PS2-1   Motion and Stability: Forces and Interactions

Students who demonstrate understanding can:

3-PS2-1. Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object. [Clarification Statement: Examples could include an unbalanced force on one side of a ball can make it start moving; and, balanced forces pushing on a box from both sides will not produce any motion at all.] [Assessment Boundary: Assessment is limited to one variable at a time: number, size, or direction of forces. Assessment does not include quantitative force size, only qualitative and relative. Assessment is limited to gravity being addressed as a force that pulls objects down.]
The performance expectation above was developed using the following elements from the NRC document A Framework for K-12 Science Education:

## Science and Engineering Practices

### Planning and Carrying Out Investigations

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.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

### Scientific Investigations Use a Variety of Methods

• Science investigations use a variety of methods, tools, and techniques.

## 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.)

## Crosscutting Concepts

### Cause and Effect

Connections to other DCIs in third grade: N/A

Articulation of DCIs across grade-levels:

Common Core State Standards Connections:

 RI.3.1 ELA/Literacy - Ask and answer questions to demonstrate understanding of a text, referring explicitly to the text as the basis for the answers. (3-PS2-1) Conduct short research projects that build knowledge about a topic. (3-PS2-1) Recall information from experiences or gather information from print and digital sources; take brief notes on sources and sort evidence into provided categories. (3-PS2-1) Mathematics - Reason abstractly and quantitatively. (3-PS2-1) Use appropriate tools strategically. (3-PS2-1) Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l). Add, subtract, multiply, or divide to solve one-step word problems involving masses or volumes that are given in the same units, e.g., by using drawings (such as a beaker with a measurement scale) to represent the problem. (3-PS2-1)

* The performance expectations marked with an asterisk integrate traditional science content with engineering through a Practice or Disciplinary Core Idea.

The section entitled “Disciplinary Core Ideas” is reproduced verbatim from A Framework for K-12 Science Education: Practices, Cross-Cutting Concepts, and Core Ideas. Integrated and reprinted with permission from the National Academy of Sciences.