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AP Physics 1 Key Concepts Review

Apr 24, 2025

AP Physics 1 Exam Review: Kinematics, Dynamics, and More

Kinematics Overview

  • Vectors vs. Scalars

    • Vectors have magnitude and direction (e.g., displacement, velocity, momentum).
    • Scalars have only magnitude (e.g., speed, energy, distance).

  • Vector Addition

    • Add vectors head to tail, include direction.
    • Break vectors into components for analysis using Pythagorean theorem.
    • Example: Projectile with initial velocity of 20 m/s; gravity affects y-direction.

  • Motion Concepts

    • Displacement: Vector (change in position) ( D_{final} - D_{initial} )
    • Distance: Scalar
    • Speed: Distance/time
    • Velocity: Displacement/time
    • Acceleration: Change in velocity over time; units ( m/s^2 )

  • Motion Graphs

    • Slope of position vs. time = velocity
    • Slope of velocity vs. time = acceleration
    • Area under velocity vs. time = displacement

  • Dot Diagrams

    • Visualize speed change: dots closer (slowing down), further (speeding up).

  • Kinematic Equations

    • Use when acceleration is constant.
    • Understand and memorize the 5 key equations, especially those not in reference tables.

  • Free Fall

    • Gravity as the sole force (ignoring air resistance).
    • Acceleration due to gravity ( 9.8 m/s^2 ).
    • Analyze motion using position, velocity, and acceleration graphs.

  • Projectile Motion

    • Angled vs. horizontal projectiles.
    • Break initial velocity into x and y components.
    • Time only affected by y-component; x-velocity affects horizontal displacement.

Dynamics Overview

  • Free Body Diagrams

    • Identify forces: gravity, friction, normal, tension.
    • Example: Constant velocity implies balance of forces.

  • Newton’s Laws

    • First Law: Objects maintain state of motion unless acted on by net force.
    • Second Law: ( F_{net} = ma ).
    • Third Law: Equal and opposite reactions.

  • Friction

    • Distinguish between static (greater) and kinetic friction.
    • Friction force ( = \mu F_{normal} ).
    • Coefficient ( \mu ) indicates surface roughness.

  • Components of Vectors

    • Apply trig to find force components in X and Y directions.

  • Elevator Problems

    • Scale reads normal force; balance against gravity and acceleration.

  • Forces on Inclines

    • Break FG into parallel and perpendicular components.
    • Friction often equals the parallel component when not accelerating.

Circular Motion and Gravitation

  • Uniform Circular Motion

    • Centripetal force causes circular motion.
    • Velocity is tangent; net force points inward.

  • Gravitation

    • Law of universal gravitation: ( F = G \frac{m_1 m_2}{r^2} ).
    • Calculate gravity on other planets: ( g = G \frac{M_{planet}}{R^2} ).
    • Orbital velocity derived from balancing centripetal and gravitational forces._

Energy Overview

  • Types of Energy

    • Gravitational potential, kinetic, and spring potential.

  • Conservation of Energy

    • Total energy remains constant in an isolated system.
    • Equation: ( K_i + U_i + W = K_f + U_f ).

  • Work

    • Change in energy, ( W = F_{\parallel}d ).
    • Work at an angle: ( W = Fd \cos \theta ).

  • Power

    • Rate of doing work: ( P = \frac{\Delta E}{\Delta t} ) or ( P = Fv )._

Momentum Overview

  • Conservation of Momentum

    • Momentum conserved in closed systems.
    • Break into components if necessary.

  • Collisions

    • Elastic: Momentum and kinetic energy conserved.
    • Inelastic: Only momentum conserved.

  • Impulse

    • Change in momentum: ( \Delta p = Ft ).
    • Area under force-time graph represents impulse.

Simple Harmonic Motion

  • Key Concepts

    • Period, frequency, and amplitude.
    • Pendulum: ( T = 2\pi \sqrt{\frac{L}{g}} ).
    • Mass-spring system: ( T = 2\pi \sqrt{\frac{m}{k}} ).

  • Graphs

    • Position, velocity, and acceleration graphs illustrate oscillation.

Torque and Rotational Motion

  • Angular Kinematics

    • Angular position, velocity, and acceleration.
    • Convert between linear and angular using radius.

  • Torque

    • Causes rotation; ( \tau = Fr \sin \theta ).
    • Torque equilibrium when net torque is zero.

  • Rotational Energy

    • Rotational kinetic energy: ( 1/2 I \omega^2 ).
    • Conservation principles apply similarly to linear motion.

  • Angular Momentum

    • Conserved if no external torque.
    • ( L = I \omega ).

These notes should help review key concepts for the AP Physics 1 exam, covering kinematics, dynamics, energy, momentum, and additional physics principles.

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