Linear motion is the motion of an object along a straight line. It is the simplest form of motion in physics. In linear motion, an object moves in one dimension, following a straight path. This red ball demonstrates linear motion as it moves along this straight line from left to right.
Position describes the location of an object relative to a reference point called the origin. Displacement is the change in position, calculated as final position minus initial position. Here we see an object moving from position negative two to position positive two, giving a displacement of four units to the right.
Velocity is the rate of change of position with respect to time. Average velocity is calculated as displacement divided by time interval. On this position-time graph, the slope of the secant line between two points represents average velocity. The orange dot shows how position changes over time.
Acceleration is the rate of change of velocity with respect to time. It measures how quickly velocity changes. On this velocity-time graph, acceleration is represented by the slope of the line. The arrows show change in velocity over change in time. Positive acceleration means speeding up, while negative acceleration means slowing down.
Kinematic equations describe motion with constant acceleration. The first equation shows velocity as a function of time. The second gives position as a function of time. The third relates velocity to displacement. This simulation demonstrates an object with initial velocity and constant acceleration, showing how position and velocity change over time.