reference Centrifugal and centripetal are two closely related forces that describe circular motion, but the meanings are often mixed up.
Radio waves help us communicate across close and far distances. They also help us identify otherwise invisible objects in space.
Resistors, inductors and capacitors are basic electrical components that make modern electronics possible.
Gamma rays are a form of electromagnetic radiation. They can be used to treat cancer, and gamma-ray bursts are studied by astronomers.
X-rays are a form of electromagnetic radiation. One of the most common uses of X-rays is for medical imaging. X-rays are also used in treating cancer and in exploring the cosmos.
Microwaves are a type of electromagnetic radiation, and are useful in communications, radar and cooking.
Humans have invented six devices that combine to make work easier. These six simple machines are the wheel and axle, the lever, the inclined plane, the pulley, the screw and the wedge.
Newton's laws of motion formalize the description of the motion of massive bodies and how they interact.
Newton's First Law of Motion states, "A body at rest will remain at rest, and a body in motion will remain in motion unless it is acted upon by an external force."
Newton’s Second Law of Motion states, “The force acting on an object is equal to the mass of that object times its acceleration.”
Ultraviolet light is a type of electromagnetic radiation. These high-frequency waves can damage living tissue.
Faraday’s Law of Induction describes how an electric current produces a magnetic field and, conversely, how a changing magnetic field generates an electric current in a conductor.
Simple harmonic motion describes the vibration of atoms, the variability of giant stars, and countless other systems from musical instruments to swaying skyscrapers.
Magnetism is the phenomenon that arises from the force between objects that produce fields that attract or repel other objects.
According to the Third Law of Thermodynamics, the entropy of a perfect crystal is zero when the temperature of the crystal is equal to absolute zero (0 Kelvin).
The Second Law of Thermodynamics says, in simple terms, entropy always increases. This principle explains, for example, why you can't unscramble an egg.
The First Law of Thermodynamics states that energy cannot be created or destroyed, but it can be transferred from one location to another and converted to and from other forms of energy.
The Zeroth Law of Thermodynamics states that if two bodies are each in thermal equilibrium with some third body, then they are also in equilibrium with each other.
Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy.
Visible light is the portion of the electromagnetic spectrum that we can see. We perceive the energy as colors.