In physics, magnitude generally refers to distance or quantity. In relation to movement, magnitude refers to the size of an object or its speed while traveling.
Distance, mass, speed and velocity in physics are divided into vectors and scalars. A vector refers to an object with two characteristics, which are magnitude and direction. Magnitude refers to an object's size or quantity, while direction means that a vector simply moves from one point to another. For example, a bowling ball has a greater magnitude than a golf ball. The bowling ball has direction when it rolls down the bowling alley. Direction describes an object's movement, and it also creates a distinction between velocity and speed.
Speed is a scalar property in physics, which means that it only describes the magnitude, or speed, of an object, and does not mention the direction that the object travels. Speed can also be described as the rate at which an object moves a certain distance. An object that moves at a fast speed is said to cover a large amount of distance in a short period of time. In contrast, an object that is traveling at a slower speed will cover a shorter distance in the same amount of time. An example of speed is stating that a car is traveling 90 miles per hour on the highway. This means that 90 is the magnitude of the car's speed. A car traveling from Virginia to Vermont may reach its end destination at the same time as a car that starts from New Jersey and travels to Vermont at a speed of 50 miles per hour.
Velocity is a vector quantity that includes speed and direction. It essentially describes the rate that it takes for a vector to change its position. Velocity, in this case, would state that a car is traveling north at a speed of 90 miles per hour on the highway. Velocity can only occur when there is change in position from the starting point to an end point. For example, a person who steps forward and then back again has a velocity of zero. Mass refers to the total volume of matter comprising an object. This property usually does not change. An object that weighs one pound on Earth, for instance, will also weigh one pound on Mars. Because mass only has one property, it is considered scalar. Weight, on the other hand, is a vector property that combines weight with the force of gravity. Weight is defined as the force of gravity acting on an object. It can be calculated as the object's mass times the weight of gravity.
The goal of physics is to describe objects in a series of quantitative physical laws. Physics is considered a natural science with applications to objects on Earth and throughout the universe. The basic laws in physics are universal. They are formed through experiments, measurements and mathematical computations. The first laws in physics date back to ancient Greece, such as Archimedes describing the buoyancy and the motions of levers. Mathematics was incorporated by physicists in the 1700s, and the modern study of physics began in the 20th century.