AP Physics 1 – Unit Summaries
A free overview of the units of algebra-based AP Physics 1, with the main ideas and relationships you need before practising problems.
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1. Kinematics
Motion is described with position, displacement, velocity and acceleration. Graphs of position, velocity and acceleration against time are linked by slopes and areas. For constant acceleration, the kinematic equations predict motion in one dimension, and projectile motion treats horizontal and vertical motion independently.
Key terms: displacement, velocity, acceleration, motion graphs, kinematic equations, projectile motion
2. Force and Translational Dynamics
Forces are interactions shown on free-body diagrams. Newton’s three laws connect net force to acceleration and describe force pairs. Friction, tension, normal and gravitational forces appear in many systems, and circular motion needs a net centripetal force. Gravitational force follows an inverse-square law.
Key terms: system, free-body diagram, Newton’s laws, friction, tension, centripetal force, gravitational field
3. Work, Energy and Power
Work transfers energy into or out of a system. Kinetic energy, gravitational potential energy and spring potential energy change as work is done, and total energy is conserved in a closed system. Power is the rate of energy transfer.
Key terms: work, kinetic energy, potential energy, conservation of energy, spring constant, power
4. Linear Momentum
Momentum is mass times velocity, and impulse changes it. In a closed system momentum is conserved, which lets you analyse collisions and explosions. Elastic collisions also conserve kinetic energy, while inelastic collisions do not. The centre of mass of a system moves as if all external forces act on it.
Key terms: momentum, impulse, conservation of momentum, elastic collision, inelastic collision, centre of mass
5. Torque and Rotational Dynamics
Rotation is described by angular displacement, velocity and acceleration. Torque depends on force and lever arm, and rotational inertia shows how mass is distributed. Newton’s second law for rotation links net torque to angular acceleration, and objects in equilibrium have zero net force and zero net torque.
Key terms: angular velocity, torque, lever arm, rotational inertia, rotational equilibrium
6. Energy and Momentum of Rotating Systems
Rotating objects have rotational kinetic energy and angular momentum. Angular momentum is conserved when no external torque acts, which explains why a spinning skater speeds up when pulling in their arms. Rolling motion combines translation and rotation.
Key terms: rotational kinetic energy, angular momentum, conservation of angular momentum, rolling without slipping
7. Oscillations
Simple harmonic motion happens when a restoring force is proportional to displacement, as in springs and pendulums. The period depends on mass and spring constant, or pendulum length and gravity, but not amplitude. Energy moves between kinetic and potential forms during each cycle.
Key terms: simple harmonic motion, restoring force, period, frequency, amplitude, pendulum
8. Fluids
Fluids are described by density and pressure. Pressure increases with depth, and buoyant force equals the weight of fluid displaced. For moving fluids, the continuity equation conserves mass flow and Bernoulli’s equation relates pressure, speed and height.
Key terms: density, pressure, buoyancy, Archimedes’ principle, continuity equation, Bernoulli’s equation
These summaries are written by Dabour Hub from the published course outline. Full notes, diagrams, quizzes and question banks are available to registered students.
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