MP Board · Class 9 · Science · MotionDefine speed and velocity. Mention their SI units.

Speed is defined as the total distance traveled by an object per unit of time. It indicates how fast an object is moving regardless of its direction of motion, making it a scalar quantity. Velocity is defined as the rate of displacement of an object per unit time, or speed in a specified direction. Since velocity includes direction, it is a vector quantity. The SI unit for both speed and velocity is meter per second ($\text{m/s}$ or $\text{m s}^{-1}$).