Chapter 3
Dynamics
Forces explain how motion changes.
Spaced review
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Forces, mass and weight
Identify force types, distinguish mass from weight and calculate weight in a given gravitational field.
Forces on one body
Draw a free-body diagram and explain the effects of balanced and unbalanced forces.
Pairs of forces
Identify forces in an interaction pair and distinguish them from forces balancing on one body.
Resultant force and acceleration
Find the combined force before using F = ma, and explain the effect of mass and inertia.
Friction and motion
Explain how friction can prevent sliding, slow a moving object or provide grip.
Three-force equilibrium
Use a closed, scaled triangle of forces to find unknown forces on a stationary point mass.
Falling with air resistance
Connect weight, drag and acceleration to changing speed and terminal velocity.