# Position Vectors, Displacement, Velocity, and Acceleration

Kinematics is the study of the position (represented by the position vector $$\vec{R}(t)$$) of an object as a function of time. The position vector can be used to define other quantities such as velocity $$\vec{v}$$ and acceleration $$\vec{a}$$; all three of these quantities, together, can fully describe the motion of any object. In this lesson, we'll study these three fundamental quantities of kinematics.

# Basic Equations of Kinematics

Galileo once pondered how one could describe the motion of cannonballs and other projectiles moving near Earth's surface. Since Aristotle, philosophers had tried for millennia to tackle this problem but it wasn't until Newton invented calculus and formulated the laws of classical mechanics when this question was finally answered. In this lesson, we'll use calculus and Newton's laws to answer this nearly 2,500 year old problem and derive the equations of motion governing projectile motion.