Projectile Motion
This photo of Baker Mayfield, Oklahoma’s sensational quarterback, passing the football is a textbook example of the physics concept of projectile motion. Projectile motion is the parabolic, or arc-like path that an object travels when influenced by horizontal and vertical components of velocity. In this case, the horizontal component is the speed resulting from the throw, and vertical consists of acceleration due to gravity. It is important to note that in assessing the value of these two velocities, physics makes one huge assumption: that air resistance is negligible. Concerning horizontal velocity, under this assumption physics maintains that it will remain constant, not accelerating, during projectile motion. Obviously, this ideal scenario is not applicable to football. It is evident in this picture that weather factors such as wind and rain (see ponchos in background) can deter the theoretical projectile motion of an object. Negligible air resistance also has implications for vertical velocity too. This assumption provides for a uniform rate of vertical acceleration of an object in projectile motion. This is not the same as the horizontal scenario. Whereas in the horizontal the projectile’s speed remained constant, in the vertical, the object does change speed, but also at a constant rate (-9.80m/s/s). This value is negative because gravity acts downward. Interestingly, assuming this, physics says that an object thrown and dropped from the same height will hit the ground at the same time. This is because gravity’s acceleration acts equally and alone on all objects in determining their vertical velocity, regardless of horizontal distance traveled. Thus, an object thrust at ground level into the air, will have a final velocity in hitting the ground equal to its initial velocity. However in the case that is object is launched at a certain height above the ground, its final velocity will exceed that of its initial value. This scenario is unique in that Baker’s arm is above the ground, but the ball could have a final velocity greater, lesser, or equal to the initial velocity depending on the position of the receiver’s hands when he catches the ball. If the receiver catches the ball above the throwing point, it’s final velocity will be slower than the initial velocity. If he catches it below, or does not catch it at all, the ball will travel faster than it did when thrown, going the extra distance from the throwing point to the hands or ground (and the same if caught at the throwing point).