  # Speed and Velocity

## definition

### Uniform Speed

Speed is a measure of how fast an object is moving at a given instant of time. It is a scalar quantity. Its unit is m/s.
For a body covering equal distances in equal time intervals, the speed is called uniform speed

## definition

### Average speed

Average speed is defined as the total distance travelled by the body in total time i.e.

It is a scalar quantity. Its unit is m/s.

## definition

### Velocity

Velocity is defined as the rate of change of displacement with time.
It is a vector quantity and has units m/s.
The direction of a velocity vector is same as the direction of the motion of body at that instant of time. Magnitude of instantaneous velocity is same as the speed at the instant.

## definition

### Uniform motion

A body is said to be in uniform motion if it moves with a constant velocity. If the magnitude and/or direction of the velocity changes, then the body is not in uniform motion.
Note:
If a body is in uniform motion, then the net external force on the body is zero. Inverse of the statement is also true (If the net external force on the body is zero, then the body is in uniform motion).

## definition

### Speed

Speed is rate of change of distance,it is the measurement of how fast or slow objects move, can be given by formula,

S.I unit of speed is

## definition

### Uniform, variable and average speed

Uniform Speed: A body is said to be moving with uniform speed, if it covers equal distances in equal intervals of time.

Variable Speed: A body is said to be moving with variable speed if it covers unequal distances in equal intervals of time.

Average Speed: Average speed of a body is defined as that uniform speed with which it covers the same distance in a given interval of time as is actually covered by it in the same interval of time while moving with variable speed.
It is given by the ratio of the total distance travelled by the body to the total time taken by it.
Average speed