Learning Outcomes
i. Define projectile motion and its characteristics.
ii. Explain why the acceleration of a projectile is always in the vertical direction.
iii. Recognize that the acceleration due to gravity (9.8 m/s²) is the sole force acting on a projectile in the vertical direction.
iv. Illustrate how gravity continuously affects the vertical velocity of a projectile.
v. Apply the concept of constant acceleration in projectile motion to solve problems.
Introduction
Projectile motion, the captivating dance of objects launched into the air, is a familiar sight in our daily lives. From the soaring arc of a thrown ball to the majestic flight of a rocket, we witness the interplay of forces and motion. While gravity plays a dominant role in shaping the projectile's path, understanding the acceleration involved in this motion provides deeper insights.
i. Gravity's Grip: Dictating Vertical Acceleration
In the realm of projectile motion, the acceleration experienced by the projectile is always directed downwards, towards the ground. This downward acceleration stems from the force of gravity, the invisible force that pulls objects towards the Earth's center. As the only force acting on the projectile in the vertical direction, gravity dictates the projectile's acceleration in this direction.
ii. The Constant Pull of Gravity: 9.8 m/s²
The magnitude of the acceleration due to gravity, denoted by 'g', is approximately 9.8 m/s². This value remains constant throughout the projectile's flight, regardless of its speed or height. This constant acceleration is what causes the projectile's vertical velocity to change continuously throughout its trajectory.
iii. Gravity's Impact on Vertical Velocity
As the projectile ascends, gravity continuously pulls it downwards, causing its vertical velocity to decrease. At the maximum height, the projectile's vertical velocity momentarily reaches zero, indicating a temporary halt in its upward motion. During the descent, gravity continues to exert its influence, causing the projectile's vertical velocity to increase, pulling it back towards the ground.
iv. Constant Acceleration: A Tool for Problem-Solving
The concept of constant acceleration in projectile motion proves valuable in solving related problems. By recognizing that the acceleration due to gravity remains constant, we can simplify calculations and gain insights into the projectile's motion.
v. Applications of Constant Acceleration
Utilizing the concept of constant acceleration, we can determine the time of flight of a projectile, its vertical displacement at any point in its trajectory, or even its velocity at any point in its flight path.
The ever-present downward pull of gravity governs the acceleration of a projectile, constantly shaping its vertical motion. Understanding this relationship between gravity and acceleration not only deepens our comprehension of projectile motion but also provides a powerful tool for analyzing and solving problems related to this fascinating phenomenon.
