ABSTRACT
However, in situations where the forces acting on the body are constant, it experiences a constant acceleration. An obvious example of this is when a body is in flight (e.g., the time when a shot putt or a long jumper is airborne) and the only force acting on it is attractive or gravitational force that exists between it and the Earth (this force is further explained in section B). This is assuming that the effect of air resistance (see section D), is negligible; which it can be for bodies of large mass traveling at low speeds. The acceleration that a body experiences as a consequence of the gravitational force varies slightly depending on its position on Earth (it is slightly greater at the poles than the equator) but is generally agreed to be equal to 9.81 m·sec−2. It should also be referred to as negative (i.e., −9.81 m·sec−2) because the acceleration acts in a downwards direction, towards the surface of the Earth. However, other constant acceleration situations can occur when a body is not airborne. For example, a cyclist who stopped pedaling on a flat road would experience a fairly constant horizontal deceleration. Similarly, providing it was traveling up or down a smooth incline, a bobsleigh would also experience an approximately constant deceleration or acceleration.
