Motion

MOTION Newton's First Law states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. It may be seen as a statement about inertia, that objects will remain in their state of motion unless a force acts to change the motion. Acceleration is a measure of how fast the velocity of an object is changing. Acceleration = change in velocity divided by time taken. If a bowling ball and a soccer ball were both dropped at the same time from the roof of a tall building, which would hit the ground with a greater force? Newton stated this relationship in his second law, the force of an object is equal to its mass times its acceleration. His third law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A. Notice that the forces are exerted on different objects. Velocity is a physical quantity. It is defined as the rate of change of distance per unit time. Common units include m/s and km/h. To convert km/h to m/s, simple divide by 3.6 and vice versa. S=d/t simply means that the speed is determined by the distance divided by time. There are relationships between these however, such as if speed increases, distance will stay same whereas time will differ. If time were changed, the distance would remain same and speed would either increase or decrease. If distance was changed, time would increase. Time always runs horizontally (the x-axis). The arrow shows the direction of time. The further to the right, the longer time from the start. Distance runs vertically (the yaxis). The higher up the graph we go, the further we are from the start.