Biomechanics > Physics > Acceleration
Acceleration
Gravity
Acceleration of an implement while in flight is constant and always -9.8 meters/second squared or 32 ft/s2 (feet per second squared); the act of gravity on the implement. Therefore, generally all objects fall to the earth at the same rate of acceleration, no matter how much they weigh. The force of gravity is always acting vertically; there is no horizontal deceleration in the absence of aerodynamic forces. Acceleration is the same regardless of the weight of the implement. Therefore, the vertical velocity of a projectile decreases by 9.8 m/s every second. Linear Acceleration
Acceleration is a measure of the time rate of change of velocity. Acceleration can be caused by a change in speed or direction or both. For example, a skater who goes from a standstill to full speed quicker than another skater has greater acceleration. Likewise, a skater who can stop quicker than another skater has greater deceleration--assuming both skaters were traveling at the same speed. Another example of acceleration is a skater who travels at a constant speed around the ice rink. In the corners, when this skater is changing direction, and thus has a changing velocity, he or she has acceleration. Acceleration is calculated by subtracting the starting velocity of an object from the final velocity, and dividing by the time between this change in velocity.
Vector
A term used to describe a quantity which has both magnitude and direction. Common examples are displacement and velocity. Both these terms are defined in this section. It is important to remember that for vector quantities the direction is just as important as the magnitude. Typically, vector quantities are represented by arrows in figures and diagrams. For example, a skater's velocity could be represented by an arrow. The length of the arrow would represent the speed (how fast) the skater was traveling, while the directi Scalar
A term