EVERYDAY SCIENCE

Detailed explanation-1: -An object is in motion if it changes position relative to a reference point. Objects that are fixed relative to Earth – such as a building, a tree, or a sign-make good reference points.

Detailed explanation-2: -If an object moves relative to a reference frame-for example, if a professor moves to the right relative to a whiteboard, or a passenger moves toward the rear of an airplane-then the object’s position changes. This change in position is known as displacement.

Detailed explanation-3: -Motion is a change in position measured by distance and time. Speed tells us the rate at which an object moves. Velocity tells us the speed and direction of a moving object. Acceleration tells us the rate at which velocity changes.

Detailed explanation-4: -An object is said to be in motion of it changes its position with time. If the position is not changing with respect to time, then the body is said to be at rest.