Skip to content
PlayOwl

Science · Grade 8

Motion, Forces and Interactions

Learners describe motion precisely with velocity and acceleration and read and draw velocity–time graphs. They use Newton's first and second laws to connect net force, mass and acceleration with F = ma calculations, identify action–reaction pairs and explain collisions with momentum, and finish by explaining how gravity depends on mass and distance and why mass and weight are different.

  • 5 lessons
  • About 120 minutes
  • Motion and forces check: 11 questions
  • Ways to answer: choose an answer, type a fraction, draw a graph, match pairs, type a number and sort into groups
Try it now (no account) One of the five free starter courses Open in PlayOwl

What learners will discover

  • Distinguish speed from velocity, calculate acceleration as change in velocity divided by time, and read and draw velocity–time graphs.
  • Use Newton's first and second laws: find the net force on an object and calculate acceleration, force or mass with F = ma.
  • Identify action–reaction force pairs (Newton's third law) and explain collisions and safety designs qualitatively using momentum (mass × velocity).
  • Explain that gravity is an attractive force that depends on the masses of objects and the distance between them, and distinguish mass from weight using W = mg.

Lessons

  1. Velocity and acceleration 9 steps5 practiceabout 22 min
  2. Velocity–time graphs 8 steps5 practiceabout 22 min
  3. Net force: Newton's first and second laws 9 steps5 practiceabout 26 min
  4. Interactions: action–reaction pairs and collisions 9 steps5 practiceabout 26 min
  5. Gravity, mass and weight 9 steps5 practiceabout 24 min
  6. Motion and forces check 11 questions at the end

Keep exploring

Games to practice with

  • Bridge LabBuild a bridge from beams, brace it with triangles, and stay on budget.
  • Circuit Workshop 3DWire up batteries, bulbs and switches on a 3D workbench.
  • River MysterySomething changed the river. Sample sites with a limited budget, follow the evidence and find where the change begins.

More 8th grade science

Guide for grown-ups