Physics Motion and Forces

Types of motion: rectilinear, circular, and periodic motion
Distance and displacement: distance is total path length, displacement is shortest distance between initial and final positions
Speed and velocity: speed is scalar, velocity is vector
Acceleration: rate of change of velocity
Equations of motion:
- v = u + at
- s = ut + 0.5at^2
- v^2 = u^2 + 2as

Force: push or pull that causes an object to change its motion
Newton's First Law (Law of Inertia): an object at rest remains at rest, an object in motion remains in motion, unless acted upon by an external force
Newton's Second Law (Law of Acceleration): force is equal to the rate of change of momentum
- F = ma
Newton's Third Law (Law of Action and Reaction): every action has an equal and opposite reaction

Work: product of force and displacement
- W = Fs
Energy: capacity to do work
- Types of energy: kinetic energy (KE), potential energy (PE)
Conservation of energy: total energy of an isolated system remains constant

Laws of reflection:
- Angle of incidence = angle of reflection
- Incident ray, reflected ray, and normal are coplanar
Laws of refraction:
- Snell's law: sin(i) / sin(r) = constant
- Total internal reflection: occurs when angle of incidence exceeds critical angle

Chemical reaction: process of transformation of one or more substances into new substances
Chemical equation: representation of a chemical reaction using chemical formulas
Types of chemical reactions: combination, decomposition, displacement, and neutralization reactions
Balancing chemical equations: ensuring that number of atoms of each element is same on both reactant and product sides

Acids: substances that donate H+ ions
Bases: substances that accept H+ ions
pH scale: measures acidity or basicity of a solution
Acid-base neutralization reaction: reaction between acid and base to form salt and water
Salts: compounds formed by reaction between acid and base

Metals: elements that are typically shiny, malleable, and good conductors of electricity
Non-metals: elements that are typically dull, brittle, and poor conductors of electricity
Physical and chemical properties of metals and non-metals
Reactivity series: arrangement of metals in order of their reactivity

Heredity: transmission of traits from parents to offspring
Inheritance of traits: determination of traits by genes
Evolution: process of change in species over time
Principles of evolution: variation, mutation, genetic drift, and natural selection

Three types of motion: rectilinear (straight line), circular (around a point), periodic (repeats over time).
Distance measures total traveled path; displacement is the straight line from start to end.
Speed is a scalar quantity (magnitude only), while velocity includes direction (vector quantity).
Acceleration is defined as the change in velocity over time.
Key equations of motion include:
- v = u + at (final velocity = initial velocity + acceleration × time)
- s = ut + 0.5at² (displacement = initial velocity × time + 0.5 × acceleration × time²)
- v² = u² + 2as (final velocity squared = initial velocity squared + 2 × acceleration × displacement).

Force is a push or pull influencing an object's state of motion.
Newton's First Law states that an object will maintain its state of rest or uniform motion unless acted on by an external force (inertia).
Newton's Second Law defines force as the product of mass and acceleration (F = ma), indicating how the velocity of an object changes with applied force.
Newton's Third Law declares that for every action, there is an equal and opposite reaction.

Work is calculated as the product of force and the distance moved in the direction of that force (W = Fs).
Energy signifies the capacity to perform work, with major types including kinetic energy (energy of motion) and potential energy (stored energy).
The conservation of energy principle asserts that in an isolated system, energy cannot be created or destroyed, only transformed.

Laws of reflection state:
- The angle of incidence is equal to the angle of reflection.
- The incident ray, reflected ray, and normal line are all in the same plane.
Laws of refraction include Snell's law, which relates the angles of incidence (i) and refraction (r) by the equation sin(i)/sin(r) = constant.
Total internal reflection occurs when the angle of incidence exceeds a specific critical angle.

A chemical reaction involves transforming one or more substances into new products.
A chemical equation uses formulas to represent the substances involved in a reaction.
Types of chemical reactions include:
- Combination (multiple reactants form one product),
- Decomposition (one compound breaks into two or more substances),
- Displacement (one element replaces another in a compound),
- Neutralization (acid and base form salt and water).
Balancing chemical equations ensures equal numbers of atoms for each element are represented on both sides.

Acids release H+ ions in solution, acting as proton donors.
Bases accept H+ ions, functioning as proton acceptors.
The pH scale quantifies the acidity or alkalinity of solutions from 0 (strong acids) to 14 (strong bases), with 7 being neutral.
Acid-base neutralization results in the formation of a salt and water.
Salts are formed when acids react chemically with bases.

Metals are generally shiny, malleable, ductile, and excellent conductors of electricity.
Non-metals, in contrast, possess a dull appearance, are brittle, and conduct electricity poorly.
Metals and non-metals exhibit distinct physical and chemical properties.
The reactivity series ranks metals based on their reactivity, guiding predictions about their behavior in reactions.

Nutrition refers to the intake of food for energy and nutrients necessary for survival.
Respiration is the metabolic process of breaking down food to release energy.
Transportation encompasses the movement of oxygen and nutrients throughout the body.
Excretion is the removal of metabolic waste products from an organism.

The nervous system regulates and coordinates physiological activities.
Neurons are specialized cells responsible for transmitting and processing information.
Reflex actions are immediate, automatic responses to stimuli requiring little conscious thought.
Hormones act as chemical messengers in the body, influencing various physiological functions.

Heredity is the genetic transmission of traits from parents to offspring.
Traits are determined by genes, which dictate characteristics.
Evolution describes gradual processes that lead to changes in species over time.
Fundamental principles of evolution include variation, mutation, genetic drift, and natural selection, explaining how species adapt and evolve.