Projectile Motion- Launched horizontally
Projectile Motion is the predictable path of an object's motion once it is initially launched. The object is then only affected by the initial launch speed, angle, and acceleration due to gravity.
In the diagram below, the blue arrow represents the horizontal velocity of an object. The horizontal velocity is kept constant when air resistance is neglected. The red arrow represents an object's vertical velocity. Once the object reaches the top of the parabola, gravity takes over and begins pushing back on the object, forcing it to fall.
Realting to Football
Projectile motions are seen frequently when a football player is kicking a field goal.
When a football player kicks a football, it is launched up in the air at a certain angle. As the ball travels, there are specific forces that act on it. Gravity pushes down on the ball, shown as a vertical vector and air resistance would be shown as the horizontal vector. If the ball is launched at a perfect 45 degree angle, the ball will have maximum range.
When a football player kicks a football, it is launched up in the air at a certain angle. As the ball travels, there are specific forces that act on it. Gravity pushes down on the ball, shown as a vertical vector and air resistance would be shown as the horizontal vector. If the ball is launched at a perfect 45 degree angle, the ball will have maximum range.
Review Questions
True or False: When air resistance is neglected, the vertical velocity of a projectile does not change.
False
A football is kicked horizontally with a speed of 50 m/s. It takes the football 10 seconds to hit the ground at the other end of the field. How high was the football when it reached maximum height?
5 m