Circular motion in the context of Linear actuator

A fishing rod or fishing pole is a long, thin rod used by anglers to catch fish by manipulating a line ending in a hook (formerly known as an angle, hence the term "angling"). At its most basic form, a fishing rod is a straight rigid stick/pole with a line fastened to one end (as seen in traditional bamboo rod fishing such as Tenkara fishing); however, modern rods are usually more elastic and generally have the line stored in a reel mounted at the rod handle, which is hand-cranked and controls the line retrieval, as well as numerous line-restricting rings (also known as line guides) that distribute bending stress along the rod and help dampening down/prevent line whipping and entanglement. To better entice fish, baits or lures are dressed onto the hook attached to the line, and a bite indicator (e.g. a float) is typically used, some of which (e.g. quiver tip) might be incorporated as part of the rod itself.

Fishing rods act as an extended lever and allow the angler to amplify line movements while luring and pulling the fish. It also enhances casting distance by increasing the launch speed of the terminal tackles (the hook, bait/lure, and other accompanying attachments such as float and sinker/feeder), as a longer swing radius (compared to that of a human arm) corresponds to greater arc speed at the tip under the same angular velocity. The length of fishing rods usually vary between 0.6 m (2 ft) and 4.6 m (15 ft) depending on the style of angling, while the Guinness World Record is 22.45 m (73 ft 7.9 in).

A crank is an arm attached at a right angle to a rotating shaft by which circular motion is imparted to or received from the shaft. When combined with a connecting rod, it can be used to convert circular motion into reciprocating motion, or vice versa. The arm may be a bent portion of the shaft, or a separate arm or disk attached to it. Attached to the end of the crank by a pivot is a rod, usually called a connecting rod (conrod).

The term often refers to a human-powered crank which is used to manually turn an axle, as in a bicycle crankset or a brace and bit drill. In this case a person's arm or leg serves as the connecting rod, applying reciprocating force to the crank. There is usually a bar perpendicular to the other end of the arm, often with a freely rotatable handle or pedal attached.

A reciprocating engine, more often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.

Tangential speed is the speed of an object undergoing circular motion, i.e., moving along a circular path. A point on the outside edge of a merry-go-round or turntable travels a greater distance in one complete rotation than a point nearer the center. Travelling a greater distance in the same time means a greater speed, and so linear speed is greater on the outer edge of a rotating object than it is closer to the axis. This speed along a circular path is known as tangential speed because the direction of motion is tangent to the circumference of the circle. For circular motion, the terms linear speed and tangential speed are used interchangeably, and is measured in SI units as meters per second (m/s).