Unit 2 · 5 lessons
Forces
Why motion changes: the forces acting on an object, the diagram that lets you see them, Newton's three laws, and friction.
- 50 practice questions
- 45 flashcards
Lessons
- 1Forces, Weight and Free-Body DiagramsWhat a force is, the handful you will actually meet, why mass and weight are different things, and how to draw the diagram that turns a word problem into a calculation.10 questions
- 2Newton's Three Laws of MotionInertia, the equation that links net force to acceleration, and the action-reaction pairs that explain how anything pushes off anything else.10 questions
- 3Net Force in One DimensionAdding forces with signs to get the net force, then feeding it into Newton's second law — including lifts, ropes and connected objects.10 questions
- 4Friction and the Coefficient of FrictionWhere friction comes from, why static friction beats kinetic, and how one number — the coefficient — links friction to the normal force.10 questions
- 5Forces in Action: Air Resistance, Terminal Velocity and SafetyWhat happens when the air is no longer ignored, why a falling object stops speeding up, and why every piece of safety equipment you have ever used works by making the stop take longer.10 questions