The purpose of the two studies presented in this paper is to establish validity evidence for the Sport Multidimensional Perfectionism Scale-2 (Sport-MPS-2: Gotwals & Dunn, 2009). Studies 1 and 2 are respectively focused on the production of structurally-related and external validity evidence.
The horizontal velocity of a projectile is constant (a never changing in value), There is a vertical acceleration caused by gravity; its value is 9.8 m/s/s, down, The vertical velocity of a projectile changes by 9.8 m/s each second, The horizontal motion of a projectile is independent of its vertical motion.
Determining the direction is a little more abstract for accelerations than velocities, however-at least until you get used to it. There are 3 things to remember: 1  The acceleration of an object is its change in velocity divided by the time. 2  If an object is moving in the positive direction, its velocity is positive. 3  Change in velocity is the ending velocity minus the starting velocity.