Vectors and Projectiles
A projectile is an object that, after it is projected or dropped, the only force upon it is gravity. A vector is represented by an arrow with a head and a tail. It shows the magnitude and the direction of the projectile.
- Any object in motion through space is considered a projectile. It may be a thrown ball, a fired bullet, a kicked football, or a thrown arrow. The path of the object through space is called its trajectory.
- Projectile trajectories are analyzed by mathematical equations of motion. In other words, things like path, distance and speed of a moving object can be calculated mathematically.
- The magnitude of a vector is represented by the length of the arrow. The lengths of individual vectors can be added together.
- The velocity, or speed, of an object can be represented by a vector. The magnitude would be the overall speed of the object and the angle of the vector arrow would show the direction.
- Projectiles have been studied since the time of Galileo who was born in 1564 and died in 1642. He studied motion and was the first person to accurately describe projectile motion.
- Vectors are referred to using alphabet letters. For example, you would have the vector a, vector b, or vector c. When referring to the magnitude of the vector, it would be written inside of parallel lines, like this ||a||.
- Projectile motion is used in sports. Any sport where balls are hit, thrown, or kicked is using projectile motion.
- When an object, like a football, is kicked it becomes a projectile. It then has two velocity components, the speed of it moving vertically and the speed of it moving horizontally. These are independent of each other and are represented by vectors. As the force of gravity affects the ball, the vertical velocity decreases. The curved path of the ball is called a parabola.
- Magnitude: When relating to vectors and projectiles, magnitude refers to the quantity or distance.
- Parabola: A symmetrical plane curve. The path of a projectile under the force of gravity ideally follows this curve.
Questions and Answers
Question: Does a basketball player consider projectile motion when shooting the ball into the hoop?
Answer: Yes, When the ball is thrown it becomes a projectile, and projectile is affected by the force of gravity. When we throw an object toward a target, we consider the effect of gravity on the object.
Watch a video showing the science of NFL Football.