Question

difference between speed and velocity

Answer 1

The short answer is that velocity is the speed with a direction, while speeddoes not have a direction. Speed is a scalar quantity—it is the magnitude of the velocity. Speed is measured in units of distance divided by time (e.g., miles per hour, feet per second, meters per second, etc.).

Answer 2

1

Definition

   Velocity can be defined as the rate at which an object changes position in a certain direction.

   The rate at which an object covers a certain distance is known as speed.

2

Type of quantity

   Vector quantity

   Scalar quantity

3

Magnitude

   Velocity can be zero, negative, or positive.

   Speed can never be negative or zero.

4

Change of direction

   The velocity of the object changes with the change in direction, therefore the object must follow one direction.

   The average speed will continue to count even if the object change direction.

5

Change with time

   Velocity can decrease with time. For a moving object, it can be 0.

   Speed never decreases with time. For a moving object, it is never 0.

6

Interrelation

   An object may possess different velocities but the same speed.

   Speed may or may not be equal to velocity.

7

Unit (SI)

   Velocity is measured in m/s

   Speed is measured in m/s

8

Equation

   = ∆x/∆t; where is the average velocity, ‘∆t’ is the time of arrival and ‘∆x’ is the displacement.

   v = d/t; where ‘v’ is the average speed, ‘t’ is time taken to travel the distance and ‘d’ is the distance travelled.

9

Example

   A train going towards south with an average speed of 50 km/h will have a velocity of 50km/h, north. An object going straight in a particular direction is considered to have velocity.

   A sports bike travelling at 50 m/s would go from 0 m/s to 30 m/s, before reaching 50 m/s and could even reach 70 m/s. However, the average speed will be the speed of the bike.