Question

define speed and velocity state its si unit​

Answer 1

Answer:

speed is rate of change of motion and its unit is m/s-1

velocity is the rate of change of speed in particular direction unit is also m/s-1 except it is displacement/time

Answer 2

Answer...

Speed

Speed of a body is the distance travelled by it per unit time. In speed the direction of motion of the body not specified. Speed has only magnitude, so speed is a scalar quantity.

$\sf \: SI \: unit \: = {m/s}^{-1}$

Velocity

Velocity of a body is the distance travelled by it per unit time in a given direction. In velocity, the direction of motion of the body is specified .Velocity has both,magnitude as well as direction , so velocity is a vector quantity.

$\sf \: SI \: unit \: = {m/s}^{-1}$