There are many examples of linear motion in everyday life, such as when an athlete runs along a straight track. Linear motion is the most basic of all motions and is a common part of life.
Based on Newton's first low of motion, any object that doesn't experience a net force will constantly move in a straight line at the same velocity, which is called linear motion. For example, if a person were pushed in outer space, they would continue moving at the same speed without ever stopping or changing direction unless another force acts upon them.
Linear motion is used constantly. An example of this is a car driving along a straight road. In fact, cars constantly transition between linear and rotational motion. According to HowStuffWorks, in a car engine, the pistons move in a linear motion, which is then converted into a rotational motion by the car's crankshaft. At the same time, the rack and pinion gearset of a car will convert the rotational motion of a steering wheel into linear motion, which turns the wheels.
Even power door locks are examples of linear motion. Using the same rack and pinion gearset that is found in cars, a lock will convert the rotational motion of a motor to linear motion to move the lock.