📘 Centripetal Force
When something moves in a circle, it’s always changing direction. Centripetal force is the force that pulls an object toward the center of the circle to kee...
Concepts
📘 Force Components
Sometimes a force isn’t acting straight up, down, or sideways. Force components break a force into parts that point along easier directions (like horizontal...
📘 Free-Body Diagrams
A free-body diagram (FBD) is a simple drawing that shows all the forces acting on an object. It helps you see what’s pushing, pulling, or lifting the object...
📘 Friction
Friction is a force that tries to stop objects from sliding or moving when they touch each other. It’s why things slow down when you push them and why you d...
📘 Inclined Planes
An inclined plane is a flat surface tilted at an angle, allowing objects to move up or down more easily than lifting them straight vertically. Studying forc...
📘 Newton’s First Law (Inertia)
Newton’s First Law, often called the law of inertia, explains that objects keep doing what they are doing unless acted on by an external force. A stationary...
📘 Newton’s Second Law (F=ma)
Newton’s Second Law explains how forces change the motion of objects. It tells us that the acceleration of an object depends directly on the net force appli...
📘 Newton’s Third Law (Action-Reaction)
Every force comes with a partner. Newton’s Third Law tells us that whenever one object exerts a force on another, the second object pushes back with an equa...
📘 Spring Force (Hooke’s Law)
A spring exerts a force when it is stretched or compressed. This force, called the spring force, always acts to restore the spring to its natural length.
📘 Systems of Objects
In physics, objects often interact. A system of objects lets us study multiple connected bodies, understanding how forces and motion affect each part and th...
📘 Types of Forces
Different forces act in different ways. Some forces pull objects downward, some push upward, and others resist motion or pull through ropes and cables.
📘 Weight and Apparent Weight
True weight is the force of gravity pulling you downward. Apparent weight is the support force pushing up on you, like the force from a floor or scale. They...
📘 Gravitational Field Strength
Gravitational field strength tells us how strong gravity is at a particular location. It describes the force per unit mass experienced by an object due to g...
📘 Kepler’s First Law
Kepler’s First Law, also called the Law of Ellipses, states that every planet moves in an elliptical orbit, with the Sun located at one focus of the ellipse...
📘 Kepler’s Second Law
Kepler's Second Law, the Law of Equal Areas, states that a line connecting a planet to the Sun sweeps out equal areas in equal intervals of time.
📘 Kepler’s Third Law
Kepler's Third Law, the Law of Harmonies, shows a precise mathematical link between a planet's orbital period and its average distance from the Sun.
📘 Orbital Speed and Period
For a satellite to maintain a stable circular orbit, the gravitational pull of the planet must provide exactly enough centripetal force to keep the satellit...
📘 Newton’s Law of Universal Gravitation
Newton's Law of Universal Gravitation states that every particle in the universe attracts every other particle with a force that is directly proportional to...
📘 Accuracy vs. Precision
In science, understanding the difference between accuracy and precision is crucial for reliable data. This page will define what each term means and show you...
📘 Dimensional Analysis
Dimensional analysis is a powerful tool in physics that goes beyond just converting units. It’s a fundamental way to understand and check equations by focus...
📘 Graphing Data and Relationships
In physics, graphs are powerful tools. They help us see patterns, understand relationships, and make predictions about how different measurements are connec...
📘 Physics Symbols and Notation
Physics uses a special language of symbols (like single letters) and short ways of writing (notation) to stand for things we measure and how they connect. L...
📘 SI Units and Base Quantities
Physics needs measurements that everyone understands, no matter where they are. That’s where the SI system comes in. It’s the standard way we measure things...
📘 Sig Figs in Addition and Subtraction
When you add or subtract measurements, significant figures follow a different rule than multiplying or dividing. For adding and subtracting, it’s all about ...
📘 Sig Figs in Multiplication and Division
When you multiply or divide measurements, the rules for significant figures are different from adding or subtracting. Here, we focus on the total number of ...
📘 Significant Figures Rules
Significant figures are a way to show how precise a measurement is. Knowing which digits are “significant” helps us avoid pretending our measurements are mo...
📘 Uncertainty
Every measurement you make has some amount of uncertainty. This is a fundamental concept in science and engineering, as it reminds us that no tool is perfec...
📘 Acceleration
Acceleration is the rate at which an object’s velocity changes. If you are speeding up, slowing down, or changing direction, you are accelerating. It is the...
📘 Distance and Displacement
Distance is the total path traveled, a scalar quantity. Displacement is the change in position from start to end, a vector quantity.
📘 Free Fall
Free fall is the motion of an object when gravity is the only force acting on it. In free fall, the object’s acceleration is constant and always directed do...
📘 Kinematics
Kinematics is the study of how objects move, focusing on their position, velocity, and acceleration without considering the forces that cause the motion.
📘 Position-Time Graphs
A position-time graph is a powerful tool that shows an object’s location over time, allowing you to quickly determine its velocity and direction of motion.
📘 Speed and Velocity
Speed tells you how fast something is going (a scalar quantity), while velocity tells you how fast and in what direction (a vector quantity).
📘 Velocity-Time Graphs
A velocity-time graph shows an object’s velocity over time. The slope of the line represents its acceleration, and the area under the curve represents its d...
📘 Projectile Motion
Projectile motion describes the curved, parabolic path an object takes when launched into the air. It’s analyzed by treating the motion as two independent c...
📘 Relative Velocity
Relative velocity is the velocity of an object as perceived from a specific frame of reference. It is a fundamental concept in kinematics, often calculated ...
📘 Uniform Circular Motion
Uniform circular motion (UCM) describes an object moving in a circular path at a constant speed. Due to its continuously changing direction, the object’s ve...
📘 Vector Addition and Subtraction
Vector addition combines two or more vectors to find a single resultant vector, often using the graphical head-to-tail method. Vector subtraction is a speci...
📘 Vectors and Scalars
A scalar quantity is a measurement that only has magnitude (a size or amount), while a vector quantity has both magnitude and a specific direction.