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Physics Exam Study Guide: Forces, Work, Energy, and Motion

Study Guide - Smart Notes

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

Exam Instructions and Calculator Settings

General Guidelines

This section outlines the rules and expectations for the exam, emphasizing academic honesty and proper problem-solving techniques.

  • Show all work: Full solutions, including equations and reasoning, are required for credit.

  • Units: All answers must include correct units.

  • Calculator mode: Ensure trigonometric functions are set correctly, e.g., , .

  • Ask for clarification: If a question is unclear, seek help during the exam.

Forces and Free-Body Diagrams

Analyzing Forces on Objects

Understanding how to draw and analyze free-body diagrams is essential for solving problems involving forces.

  • Free-body diagram: A graphical representation showing all forces acting on an object.

  • Types of forces: Tension, gravity (weight), normal force, friction, applied force.

  • Newton's Second Law:

  • Components of forces: Forces can be resolved into x and y components using trigonometry.

Example: For a ball of mass 0.4 kg moving in a horizontal plane at 0.7 m/s, the tension in the string provides the centripetal force required for circular motion.

  • Centripetal force:

  • Tension components: ,

Work, Energy, and Power

Work Done by Forces

Work is the transfer of energy via a force acting over a distance. The work done by different forces can be calculated using their respective formulas.

  • Work by a constant force:

  • Gravitational work:

  • Work-energy theorem:

Example: Calculating the work done by the gravitational force on a block sliding down an incline.

Power

Power is the rate at which work is done or energy is transferred.

  • Definition:

  • Application: Engine power required to accelerate a car.

Friction and Inclined Planes

Static and Kinetic Friction

Frictional forces oppose the motion of objects and are classified as static (preventing motion) or kinetic (opposing ongoing motion).

  • Static friction:

  • Kinetic friction:

  • Normal force: The perpendicular contact force exerted by a surface.

Example: Calculating the frictional force and normal force for a block on an inclined plane.

Spring Force and Hooke's Law

Elastic Potential Energy

Springs store energy when compressed or stretched, described by Hooke's Law and elastic potential energy.

  • Hooke's Law:

  • Elastic potential energy:

  • Work done by spring:

Example: A block attached to a spring is pulled and released; calculate its speed using energy conservation.

Impulse and Momentum

Collisions and Conservation of Momentum

Momentum is conserved in isolated systems. Impulse is the change in momentum resulting from a force applied over time.

  • Momentum:

  • Impulse:

  • Conservation of momentum:

Example: A ball collides with the ground and bounces back; calculate the impulse and final velocity.

Summary Table: Forces on an Inclined Plane

This table summarizes the main forces acting on a block on an inclined plane and their formulas.

Force

Formula

Direction

Weight (Gravity)

Downward

Normal Force

Perpendicular to surface

Friction (Kinetic)

Opposite to motion

Applied Force

Parallel to surface

Additional info:

  • Some diagrams and equations were inferred from context and standard physics curriculum.

  • All equations are provided in LaTeX format for clarity.

  • Examples and applications are based on typical introductory physics problems.

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