Unit Plan 9 (Grade 3 Science): Forces & Motion — Quarter Synthesis

Focus: Explain how forces, motion patterns, and magnetic interactions work together and apply this understanding to a simple engineering challenge.

Grade Level: 3

Subject Area: Science (Physical Science • Engineering/Design)

Total Unit Duration: 5 sessions (one week), 45–60 minutes per session

I. Introduction

In this quarter-synthesis unit, students bring together everything they’ve learned about forces and motion: pushes and pulls, balanced vs. unbalanced forces, motion patterns, and magnetism. Through review stations, mini-investigations, and a culminating design project, they revisit how to measure and describe motion, recognize patterns that help predict future motion, and explain magnetic forces at a distance. By the end of the week, they use this knowledge to design or improve a magnet-based solution and create a Forces & Motion Showcase product.

Essential Questions

• How do forces (pushes and pulls) change the motion of objects?
• How can we use patterns in motion to predict what will happen next?
• In what ways do magnets interact with different materials and with each other, even at a distance?
• How can scientists and engineers use forces and magnets to solve real-world problems?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Explain, using evidence, how balanced and unbalanced forces affect an object’s motion (speed up, slow down, change direction, or stay still).
2. Make and interpret measurements/observations of motion to describe patterns and use those patterns to predict future motion.
3. Ask and answer questions about magnetic interactions (attraction, repulsion, distance effects, and materials magnets act on).
4. Define and carry out a simple magnet-based design problem, generating and comparing multiple solutions that apply force and motion ideas.
5. Create a Forces & Motion Showcase (poster, booklet, or model) that clearly connects forces, motion patterns, and magnet interactions, using data and diagrams.

Standards Alignment — 3rd Grade (NGSS-Aligned)

• 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.
  • Example: Use different pushes on a cart and observe how speed and direction change.
• 3-PS2-2 — Make observations or measurements of an object’s motion to provide evidence that a pattern can be used to predict future motion.
  • Example: Track a rolling ball’s path and use that pattern to predict where it will go next.
• 3-PS2-3 — Ask questions about cause-and-effect relationships of electric or magnetic interactions between two objects not in contact.
  • Example: Ask how distance changes the strength of attraction/repulsion between magnets.
• 3-PS2-4 — Define a simple design problem that can be solved by applying scientific ideas about magnets.
  • Example: Create a tool that uses magnets to move or sort small metal objects.
• 3-5-ETS1-1 — Define a simple design problem with specified criteria and constraints.
  • Example: Design a magnet-powered “rescue device” that must carry 5 paper clips across a gap.
• 3-5-ETS1-2 — Generate and compare multiple solutions based on how well they meet criteria and constraints.
  • Example: Compare two magnet-cart designs for speed, control, and reliability.
• 3-5-ETS1-3 — Plan and carry out fair tests with controlled variables to identify improvements to designs.
  • Example: Test magnet devices while keeping distance and ramp angle the same, then revise.

Success Criteria — Student Language

• I can describe and show what happens when forces on an object are balanced or unbalanced.
• I can measure and record an object’s motion and use patterns in my data to predict what it will do next.
• I can ask and answer questions about how magnets pull or push on objects, even without touching.
• I can plan, build, test, and improve a simple device that uses magnets to solve a problem.
• I can create a final product that clearly explains forces, motion patterns, and magnets using diagrams, labels, and data.