Science Quarter 1: Types of Forces

Types of Forces

• Friction: Force generated by the contact and sliding of two surfaces.
• Tension: Force transmitted through a rope, string, or wire when pulled from opposite sides.
• Gravity: Attracts any two objects with mass toward each other.
• Normal Force: Prevents solid objects from passing through each other.
• Applied Force: Force exerted on an object by a person or another object.

Newton’s Laws of Motion

• Law of Inertia: Objects remain at rest or maintain motion unless acted upon by an external force; inertia is resistant to change in motion and is measured by mass.
• Law of Acceleration: Acceleration depends on force and mass, described by the formula F = ma; direct relationship with force and inverse with mass.
• Law of Interaction: "For every action, there is an equal and opposite reaction."

Balanced and Unbalanced Forces

• Balanced Forces: Equal in magnitude, net force is zero, resulting in no change in motion.
• Unbalanced Forces: Not equal in magnitude, net force is non-zero, resulting in a change in motion.

Combining Forces

• Formula: Fnet = Fg + Fn.
• Addition of forces with like signs, subtraction with unlike signs.

Kinetic and Potential Energy

• Energy: Ability to perform work; cannot be created or destroyed, only altered.
• Kinetic Energy: Energy of motion, dependent on mass and velocity; calculated using formula ½ mv².
• Potential Energy: Stored energy based on position or height; calculated with PE = mgh (mass × gravity × height).

Sound Waves

• Sound is produced by vibrating objects; it is a longitudinal wave requiring a medium to travel.
• Speed Factors: Affected by the state of matter, temperature, and rigidity of the medium.
• Speed of Sound Formula: v = 331 m/s + 0.6 m/s/C (temperature).
• Key Concepts:
  • Echo: Reflected sound.
  • Reflection: Turning back of a wave upon hitting a barrier.
  • Refraction: Change in speed of sound in different densities.
  • Amplitude: Strength of sound waves, perceived as loudness.
  • Reverberation: Multiple sound reflections.

Light Waves

• Visible Spectrum: The portion of the electromagnetic spectrum visible to the human eye.
• Light can travel in a vacuum; wavelength inversely proportional to frequency and energy.
• Color Properties: Red has the longest wavelength (lowest frequency/energy); violet has the shortest (highest frequency/energy).
• Light Properties:
  • Reflection: Bouncing back of light from smooth surfaces.
  • Refraction: Bending of light between different mediums.
  • Dispersion: Splitting of white light into colors due to wavelength differences.

Thermal Energy

• Transferred between objects due to temperature differences; total kinetic energy of particles.
• Heat Absorption Phases: Melting, evaporation, sublimation.
• Heat Release Phases: Freezing, condensation, deposition.

Temperature vs. Heat

• Temperature: Measured in Celsius, Fahrenheit, Kelvin; average kinetic energy degree of hotness (Symbol: T).
• Heat: Measured in calories, Joules; total kinetic energy quantity of hotness (Symbol: Q).

Current vs. Voltage

• Current: Flow of electrical charge carriers in a circuit; symbol I; measured in Amperes.
• Voltage: Electrical potential difference; symbol V; measured in Volts; causes current flow.

Resistance

• Opposes current flow, measured in ohms; described by relationship: V = IR (voltage = current × resistance).
• Current directly proportional to voltage and inversely proportional to resistance.

Series and Parallel Circuits

• Series Circuit: Single path for current; failure in one part affects the whole circuit.
• Parallel Circuit: Branching paths; if one branch fails, others continue functioning.
• Key Terms:
  • Short circuit: Current takes a path with less or zero resistance.
  • Grounded circuit: Current flows from positive conductor to the ground.
  • Thermal hazard: Electrical overheating risk.
  • Shock hazard: Current passing through a person.

Safety Devices

• Fuse: Melts if current exceeds its rating.
• Circuit Breaker: Opens switch during overload using electromagnets.
• Earthing/Grounding: Protects users by connecting appliances to the earth.
• UPS: Provides emergency power during disruptions.

This quiz reviews the various types of forces covered in Quarter 1 of your Science curriculum. Topics include friction, tension, gravity, normal force, and applied force among others. Test your understanding of these fundamental concepts in physics.