Velocity

The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of its speed and direction of motion (e.g. 7001166666666666666♠60 km/h to the north). Velocity is an important concept in kinematics, the branch of classical mechanics that describes the motion of bodies.

Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called "speed", being a coherent derived unit whose quantity is measured in the SI (metric) system as metres per second (m/s) or as the SI base unit of (m⋅s⁻¹). For example, "5 metres per second" is a scalar (not a vector), whereas "5 metres per second east" is a vector.

If there is a change in speed, direction, or both, then the object has a changing velocity and is said to be undergoing an acceleration.

Constant velocity vs acceleration

To have a constant velocity, an object must have a constant speed in a constant direction. Constant direction constrains the object to motion in a straight path thus, a constant velocity means motion in a straight line at a constant speed.

Velocity (software development)

Velocity is a capacity planning tool sometimes used in Agile software development. Velocity tracking is the act of measuring said velocity. The velocity is calculated by counting the number of units of work completed in a certain interval, the length of which is determined at the start of the project.

Principle

The main idea behind velocity is to help teams estimate how much work they can complete in a given time period based on how quickly similar work was previously completed.

Terminology

The following terminology is used in velocity tracking.

Usage

To calculate velocity, a team first has to determine how many units of work each task is worth and the length of each interval. During development, the team has to keep track of completed tasks and, at the end of the interval, count the number of units of work completed during the interval. The team then writes down the calculated velocity in a chart or on a graph.

The first week provides little value, but is essential to provide a basis for comparison. Each week after that, the velocity tracking will provide better information as the team provides better estimates and becomes more used to the methodology.

Velocity (TV channel)

Velocity (formerly HD Theater and originally Discovery HD Theater) is an American high-definition, commercial-based, cable and satellite television channel owned by Discovery Communications. The channel specializes in nonfictional programming, focusing on cars, sports related shows, and other programming targeted at men ages 18–54.

As of February 2015, approximately 62.3 million American households (53.5% of households with television) receive Velocity.

History

The channel launched nationwide in the United States on June 17, 2002, as Discovery HD Theater. The channel was rebranded to HD Theater on September 22, 2007, because Discovery Communications launched HD simulcasts of some of its other channels including Animal Planet, Discovery Channel, Science and TLC.

On April 14, 2011, Discovery Communications announced that HD Theater would be re-launched as Velocity later in the year: aimed primarily at an "upscale male" audience, the network focuses primarily on automotive-oriented programming and other shows of interest to a male audience. The re-launch took place on October 4, 2011.