Science·Forces & Motion·conceptual
Resultant Forces
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)
Suggested ages 11–12
Evidence of understanding
- 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 Resultant Forces 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?
Standards alignment
MS-PS2-1US · ngss-ms
MS-PS2-1
Next Generation Science Standards (NGSS) Middle School
KS3.Sci.Phys.MotionAndForces.4GB · uk-nc-2013
Forces as Vectors
The national curriculum in England: Key stages 1 and 2 framework document · KS3