---Newton’s first Law is also known as the law of inertia. It says that every object continues in a state of rest, or of motion in a straight line at a constant speed, unless it is compelled to change that state by forces exerted upon it. Inertia is the reluctance of any body to change its state of motion. Mass is the measure of inertia. Equilibrium is the state of a body on which no net force acts. Objects tend to keep doing what they were doing, so when a body is at rest it tends to stay at rest. Constant velocity requires both constant speed and constant direction to be constant velocity. Basically objects just keep doing what they were doing. Objects stay the same unless an unbalanced force acts upon them. Newton’s first law is a newer version of Galileo’s idea.
---There are many different examples of Newton’s first law. When you are riding an elevator downwards and the elevator stops quickly, your blood rushes down your body towards your feet. Another example would be if you were riding a bicycle and you ran into a curb you would instantly fly forward. If you throw an object out of a moving plane the object will continue at the same speed the airplane was traveling at. These are just a few examples of Newton’s first law.