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Comprehensive Study Notes for Introductory Physics (PHY 161)

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Vectors and Vector Operations

Vector Addition and Subtraction

Vectors are quantities that have both magnitude and direction. They can be added or subtracted graphically or algebraically.

  • Vector Addition:

  • Vector Subtraction:

Scalar (Dot) Product

  • Definition:

  • Component Form:

Vector (Cross) Product

  • Definition:

  • Component Form:

Right-Hand Rule

  • Used to determine the direction of the cross product.

  • Point fingers in the direction of , curl toward ; thumb points in the direction of .

Kinematics: Motion in One and Two Dimensions

Kinematic Equations (Horizontal & Vertical)

Kinematic equations describe the motion of objects under constant acceleration.

Projectile Motion

  • Horizontal velocity:

  • Vertical velocity:

  • Vertical motion uses kinematic equations with (gravity).

Example:

A ball is thrown at an angle with initial velocity . Maximum height is found using vertical component and at the top.

Newton's Laws and Forces

Newton's Laws of Motion

  • First Law: An object remains at rest or in uniform motion unless acted on by a net force.

  • Second Law:

  • Third Law: For every action, there is an equal and opposite reaction.

Contact Forces

  • Normal Force: Perpendicular to the surface.

  • Friction Force: Parallel to the surface, opposes motion.

  • Tension Force: From a stretched rope or cord.

Inclined Planes and Circular Motion

  • Inclined Plane: (tension or force along the incline)

  • Circular Motion: ,

Work, Energy, and Power

Work Done by a Force

  • For a varying force:

Kinetic Energy and Work-Energy Theorem

  • Kinetic Energy:

  • Work-Energy Theorem:

Potential Energy

  • Gravitational PE:

  • Elastic PE (spring):

Power

  • Average:

  • Instantaneous:

Conservation Laws

Conservation of Energy

  • Total mechanical energy (if only conservative forces):

Conservation of Momentum

  • Momentum:

  • Impulse:

  • Conservation: (if )

Collisions

  • Elastic: Kinetic energy and momentum conserved.

  • Inelastic: Only momentum conserved.

Center of Mass

Rocket Propulsion

Rotational Motion

Rotational Kinematics

  • Angular displacement: (radians)

  • Angular velocity:

  • Angular acceleration:

  • Kinematic equations (analogous to linear):

Moment of Inertia and Rotational Energy

  • Moment of Inertia:

  • Rotational Kinetic Energy:

Torque and Angular Momentum

  • Torque:

  • Newton's Second Law for Rotation:

  • Angular Momentum:

  • Conservation: If , is constant.

Direction Conventions

  • Clockwise: negative

  • Counterclockwise: positive

Summary Table: Key Equations

Quantity

Equation

Displacement

Velocity

Kinetic Energy

Potential Energy

Work

Momentum

Impulse

Torque

Angular Momentum

Moment of Inertia

Additional info:

  • These notes cover core topics from introductory physics, including vectors, kinematics, Newton's laws, work and energy, momentum, and rotational motion.

  • Formulas are provided in both symbolic and component forms where relevant.

  • Examples and diagrams are referenced to illustrate applications of the equations.

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