AP Physics 1 Exam Review Notes
Kinematics Overview
- Kinematics studies the motion of objects.
- Important concepts include displacement, velocity, acceleration, and the distinction between vectors and scalars.
Vectors vs. Scalars
- Vectors: Have both magnitude and direction (e.g., displacement, velocity, momentum).
- Scalars: Have only magnitude (e.g., speed, energy, distance).
- When adding vectors, use the head-to-tail method and account for direction.
Breaking Vectors into Components
- Use the Pythagorean theorem to analyze motion in components (X and Y directions).
- Example: A ball launched with an initial velocity of 20 m/s affected separately by gravity in Y direction.
Displacement and Distance
- Displacement (D): Change in position, represented as a vector; calculated as final position minus initial position.
- Distance: Total path traveled, a scalar quantity.
- Example: Walking forward 10 steps and back 5 steps: Distance = 15 steps, Displacement = 5 steps.
Motion Graphs
- Understand how to interpret motion graphs (position, velocity, and acceleration).
- Position vs. Time Graph: Slope represents velocity.
- Velocity vs. Time Graph: Slope represents acceleration.
- Area under curves: Represents displacement for velocity-time graphs and change in velocity for acceleration-time graphs.
Kinematic Equations
- Use when acceleration is constant.
- Common equations include:
- v = u + at
- s = ut + 0.5at²
- v² = u² + 2as
- Variables:
- v = final velocity
- u = initial velocity
- a = acceleration
- s = displacement
Free Fall
- Only the force of gravity acts on the object; acceleration due to gravity (g) = 9.8 m/s².
- Analyze motion using kinematic equations.
Projectile Motion
- Break initial velocity into horizontal and vertical components.
- Horizontal motion: Constant velocity, no acceleration.
- Vertical motion: Accelerated motion due to gravity.
- Time is the same for both directions.
Dynamics Overview
- Study of forces and their effects on motion.
Free Body Diagrams
- Illustrate all forces acting on an object.
- Common forces:
- Force of Gravity (Fg): Always downward.
- Normal Force (Fn): Perpendicular to surface.
- Friction: Opposes motion.
- Tension: Force from strings or ropes.
Newton's Laws of Motion
- First Law: An object at rest stays at rest; an object in motion stays in motion unless acted upon by a net external force.
- Second Law: F = ma (Net force results in acceleration).
- Third Law: For every action, there is an equal and opposite reaction.
Friction
- Static Friction: Opposes initial motion; generally greater than kinetic friction.
- Kinetic Friction: Opposes motion once it has started.
- Friction Formula: F_friction = µ * F_normal, where µ is the coefficient of friction.
Systems and Accelerations
- Treat systems as one object for analyzing forces and accelerations.
- Use F = ma to solve for tensions and other forces within a system.
Forces on Inclines
- Resolve gravity into components (parallel and perpendicular) relative to the incline.
Circular Motion and Gravitation Overview
- Centripetal Force: Required for circular motion, directed towards the center of the circle.
- Newton’s Law of Gravitation: F_g = G * (m1 * m2) / r², where G is the gravitational constant.
- Calculate acceleration due to gravity (g) on other planets using: g = G * M/R².
Energy Overview
- Types of Energy:
- Gravitational Potential Energy (GPE): GPE = mgh.
- Kinetic Energy (KE): KE = 1/2 mv².
- Spring Potential Energy: U = 1/2 kx², where k is the spring constant, and x is the displacement from equilibrium.
Conservation of Energy
- In a closed system, energy is conserved: E_initial = E_final.
Work Overview
- Work = F * d * cos(θ).
- Positive work increases energy, negative work decreases energy.
Momentum Overview
- Momentum (p): p = mv, a vector quantity.
- Conservation of Momentum: Total momentum of a closed system remains constant in the absence of external forces.
Types of Collisions
- Elastic Collisions: Both momentum and kinetic energy conserved.
- Inelastic Collisions: Momentum conserved; kinetic energy lost.
- Perfectly Inelastic Collisions: Objects stick together post-collision, resulting in maximum kinetic energy loss.
Simple Harmonic Motion (SHM)
- Repetitive motion around an equilibrium position due to a restoring force.
- Key terms:
- Period (T): Time for one full cycle.
- Frequency (f): Number of cycles per second.
- Amplitude: Maximum displacement from equilibrium.
Example Systems
- Pendulum: T = 2π√(L/g) (independent of amplitude).
- Spring-Mass System: T = 2π√(m/k) (independent of amplitude).
Rotational Motion Overview
- Angular Position (θ), Angular Velocity (ω), Angular Acceleration (α).
- Connects to linear motion through the radius.
- Torque (τ): τ = r * F * sin(θ), causes angular acceleration.
- Rotational Energy: KE_rotational = 1/2 Iω², where I is the moment of inertia.
Conservation of Angular Momentum
- Analogous to linear momentum. If no external torque acts, angular momentum is conserved.
These notes serve as a comprehensive review guide for AP Physics 1 exam topics, particularly focused on Kinematics, Dynamics, Circular Motion, Gravitation, Energy, Momentum, Simple Harmonic Motion, and Rotational Motion.