C Curriculum Explorer
Science·Forces & Motion·procedural

Balanced & Unbalanced Forces

Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object

Suggested ages 8–9

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Learning journey

Your child is investigating how forces affect movement — observing patterns in how objects move and conducting experiments to understand how balanced and unbalanced forces change an object's motion.

Evidence of understanding

  • Define balanced forces (equal in size, opposite in direction — no change in motion) and unbalanced forces (cause motion to change)
  • Plan a fair test investigating how different force sizes affect an object's motion
  • Use results as evidence to explain when forces are balanced versus unbalanced

Assessment prompt

Can Balanced & Unbalanced Forces explain why a book sitting on a table doesn't move (balanced forces) but slides when you push it (unbalanced forces)?

Standards alignment

3-PS2-1US · ngss-k5

3-PS2-1

Next Generation Science Standards (NGSS) K-5