Horizontal projectile motion is the motion of an object thrown horizontally under the influence of gravity only. The object has an initial horizontal velocity and follows a parabolic trajectory. Key characteristics include horizontal initial velocity, constant gravitational acceleration downward, and a parabolic path.
Horizontal projectile motion can be decomposed into two independent motions. In the horizontal direction, the object moves with constant velocity since no horizontal force acts on it. In the vertical direction, the object undergoes free fall motion with constant downward acceleration due to gravity. These two motions are independent and can be analyzed separately.
The motion equations for horizontal projectile motion are derived from the decomposition. For horizontal motion, velocity remains constant at v zero, and position is v zero times t. For vertical motion, velocity increases linearly with time as g t, and position follows the free fall equation y equals one half g t squared. Combining these gives the trajectory equation y equals g over two v zero squared times x squared, which is a parabola.
The velocity of a projectile has two components. The horizontal component remains constant at v zero throughout the motion. The vertical component increases linearly with time as g t. The magnitude of the total velocity is the square root of v x squared plus v y squared. The direction of velocity changes continuously, with the angle theta given by the arctangent of v y over v x.
To summarize what we have learned about horizontal projectile motion: It combines uniform horizontal motion with vertical free fall. The motion can be analyzed separately in each direction using independent equations. The trajectory follows a parabolic path, and the velocity changes continuously in both magnitude and direction. These fundamental principles help us understand and predict projectile motion in many real-world applications.