A machine is a physical system that uses power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromolecules, such as molecular machines. Machines can be driven by animals and people, by natural forces such as wind and water, and by chemical, thermal, or electrical power, and include a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement. They can also include computers and sensors that monitor performance and plan movement, often called mechanical systems.
A Honda F1 racecar engine
A flint hand axe was found in Winchester.
The Kinematics of Machinery (1876) has an illustration of a four-bar linkage.
Diesel engine, friction clutch and gear transmission of an automobile
In physics, motion is when an object changes its position with respect to a reference point in a given time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and frame of reference to an observer, measuring the change in position of the body relative to that frame with a change in time. The branch of physics describing the motion of objects without reference to their cause is called kinematics, while the branch studying forces and their effect on motion is called dynamics.
A car is moving in high speed during a championship, with respect to the ground the position is changing according to time hence the car is in relative motion
Image: Velocity vs time graph for average acceleration that shows dependence on time