Define and differentiate between speed and velocity.

Speed is the rate at which an object moves, while velocity is the rate at which an object moves in a specific direction.

Speed is a scalar quantity, meaning it only has magnitude and no direction. It is calculated by dividing the distance travelled by the time taken. The formula for speed is:

Speed = Distance/Time

For example, if a car travels 100km in 2 hours, its speed would be:

Speed = 100km/2 hours = 50km/hour

Velocity, on the other hand, is a vector quantity, meaning it has both magnitude and direction. It is calculated by dividing the displacement (change in position) by the time taken. The formula for velocity is:

Velocity = Displacement/Time

For example, if a car travels 100km north in 2 hours, its velocity would be:

Velocity = 100km north/2 hours = 50km/hour north

It is important to note that velocity takes into account the direction of motion, while speed does not. Therefore, two objects can have the same speed but different velocities if they are moving in different directions.