← Home

Resultant Forces

CONCEPTUAL
Science›Forces & Motion|Ages 11—12|ID: mt_AiWlJfvC3O

Describe forces as vector quantities with both magnitude and direction, distinguish between balanced forces (zero resultant, no change in motion) and unbalanced forces (non-zero resultant, causes acceleration or deceleration)

Mastery Evidence

  • Explains what a vector quantity is and why force is a vector
  • Calculates the resultant force when two forces act in the same or opposite directions on an object
  • Explains what happens to an object's motion when forces are balanced vs unbalanced
  • Draws free body diagrams showing all forces on a stationary object (e.g. a book on a table)

Assessment Prompt

“If [child] was pushing a heavy box along the floor but it wasn't moving, could they explain all the forces acting on it and why it stays still even though you're pushing?”

Curriculum Standards2 alignments

MS-PS2-1Next Generation Science Standards (NGSS) Middle Schoolcodes only
Standard code — full text not included in this dataset.
KS3.Sci.Phys.MotionAndForces.4The national curriculum in England
Forces as Vectors

forces as vectors; balanced and unbalanced forces; a stationary object and forces acting on it

Science · KS3

Prerequisites4

Show full prerequisite tree
  • Pushes & Pulls hard

    KS3 forces as vectors extends KS2 introduction to pushes and pulls changing speed and direction

    • Drawing Force Diagrams soft

      Understanding pushes and pulls as forces is supported by the arrow representation of magnitude and direction

  • Force & Motion Vocabulary hard

    Describing balanced and unbalanced forces as vector quantities requires resultant force, balanced forces vocabulary

  • Drawing Force Diagrams hard

    Forces as vectors with magnitude and direction is the formal underpinning of the force arrow representation

  • Contact & Non-Contact Forces hard

    KS3 resultant force and balanced forces extends KS2 distinction between contact and non-contact forces

    • Forces Vocabulary hard

      Distinguishing contact from non-contact forces requires these exact terms

    • Drawing Force Diagrams soft

      Distinguishing contact and non-contact forces is clarified by drawing force diagrams showing where arrows originate

    • Friction & Surfaces hard

      Must experience contact forces like friction before distinguishing contact vs non-contact forces

      • Pushes & Pulls hard

        Must understand forces change motion before comparing movement on different surfaces

        • Drawing Force Diagrams soft

          Understanding pushes and pulls as forces is supported by the arrow representation of magnitude and direction

      • Forces Vocabulary hard

        Comparing how things move on different surfaces requires friction vocabulary

Unlocks4