Arouex: think of a bicycle standing upside down and the wheels free to spin. They wont spin on their own until outside force acts on them
ex: when a car accelerates and u feel like u are pushed back into the chair
ex: a ball rolling down a slippery slope onto a flat surface will keep going until it hits something
ex: the earth revolves around the sun and has done so far maybe 5 billion years. It velocity around the sun does not change because there is no force acting on its speed it up or slow it down
ex: when ur friend is standing and u push him, he moves forward, it is based on force of how hard u push him