De Broglie Wavelength Formula

In some situations, light behaves like a wave, while in others, it behaves like particles. The particles of light are called photons, and they can be thought of as both waves and particles. Louis de Broglie (1892-1987) developed a formula to relate this dual wave and particle behavior. It can also be applied to other …

Kinetic Friction Formula

Kinetic friction is a force that acts between moving surfaces. An object that is being moved over a surface will experience a force in the opposite direction as its movement. The magnitude of the force depends on the coefficient of kinetic friction between the two kinds of material. Every combination is different. The coefficient of …

Inelastic Collision Formula

An inelastic collision is any collision between objects in which some energy is lost. A special case of this is sometimes called the "perfectly" inelastic collision. In a perfectly inelastic collision, two objects collide and stick together. The momentum of the objects before the collision is conserved, but the total energy is not conserved. The …

Escape Velocity Formula

The escape velocity is the minimum velocity required to leave a planet or moon. For a rocket or other object to leave a planet, it must overcome the pull of gravity. The formula for escape velocity contains a constant, G, which is called the "universal gravitational constant". Its value is  . The unit for escape velocity is …

Stopping Distance Formula

If a driver puts on the brakes of a car, the car will not come to a stop immediately. The stopping distance is the distance the car travels before it comes to a rest. It depends on the speed of the car and the coefficient of friction (μ) between the wheels and the road. This …

Flow Rate Formula

The flow rate of a liquid is a measure of the volume of liquid that moves in a certain amount of time. The flow rate depends on the area of the pipe or channel that the liquid is moving through, and the velocity of the liquid. If the liquid is flowing through a pipe, the …

Center of Mass Formula

The center of mass is a point of balance of an object or a group of objects. The center of mass can be found for any one, two-, or three-dimensional object, and so the units are meters (m) in each dimension. The formula given here is for the center of mass in one dimension. X = …

Angular Momentum Formula(Moment of Inertia and Angular Velocity)

Angular momentum relates to how much an object is rotating. An object has a constant angular momentum when it is neither speeding up nor slowing down. The angular momentum of an object depends on the distribution of the mass of the object. The moment of inertia is a value that describes the distribution. It can …

Air Resistance Formula

Air resistance is a force that affects objects that move through the air. Often physics problems used in teaching ignore it, but it is very important for understanding the motion of fast-moving objects like airplanes. It depends on the density of the air, the area of the object, the velocity it is moving, and a …

Work Formula

Work is the result when a force acts on an object and moves it by some distance. Sometimes, the direction an object moves is not the same as the direction of the force. In that case, only the component of the force that acts in the direction of the movement causes work to be done. …