Displacement is the shortest distance between the starting and ending point of an object’s motion in a specific direction, while distance is the total length of the path traveled by an object. In other words, displacement is a vector quantity that includes both magnitude and direction, while distance is a scalar quantity that only includes magnitude.
Velocity and speed are both measurements of an object’s motion, but they differ in that velocity includes direction and speed does not. Velocity is a vector quantity, while speed is a scalar quantity. For example, a car traveling at 50 miles per hour due east has a velocity of 50 mph, while a car traveling at 50 miles per hour in any direction has a speed of 50 mph.
Acceleration is the rate at which an object’s velocity changes. It is calculated by dividing the change in velocity by the change in time. The unit for acceleration is meters per second squared (m/s²). If an object’s velocity increases by 10 m/s over a time of 5 seconds, the acceleration would be 2 m/s².
Projectile motion is the motion of an object that is launched into the air and then moves under the influence of gravity alone. Examples of projectile motion include a basketball being thrown into the air, or a rocket being launched into space.
Air resistance is a force that acts in the opposite direction of an object’s motion through the air. It can slow down the speed of an object and change its trajectory. The larger the surface area of an object, the greater the air resistance it experiences. For example, a feather will experience more air resistance than a bullet due to its larger surface area.