When an object, orbiting in circular path, experiences the sensation of being thrown outward away from the of circle. We often think that an outward force or centrifugal force is responsible for this trend. But it is wrong idea. Inertia is responsible for this. Since earth rotates around its axis, an object standing on the surface of earth rotates with earth. We say that it affect the downward force that object feels while standing on the surface of earth, and to calculate the net value of attraction force between earth and object we subtract the value of centrifugal force from the weight of that object. This is because centrifugal force pulls this object outward, and the value of centrifugal force equals to that of centripetal force. But we know that centrifugal force is not responsible for the sensation of being thrown from the of circle. So why, in the case of effect of earth's rotation on value of gravitational force, do we think that centrifugal force wants to pull the object to outward?