Speed and velocity are two
related but distinct concepts in physics.
Speed refers to the rate at which an object covers
a distance. It is a scalar quantity, meaning it has only magnitude and no
direction. It is typically measured in units of distance per unit of time, such
as meters per second (m/s) or kilometers per hour (km/h).
Velocity, on the other hand, is a vector quantity
that refers to both the speed of an object and the direction in which it is
moving. It is measured in units of distance per unit of time, but also includes
a direction.
For example, if a car is traveling at a speed of 60
km/h, its velocity would be 60 km/h to the east or 60 km/h to the west,
depending on the direction in which it is moving.
It's important to note that an object can have a
constant speed but changing velocity if it is changing direction. On the other
hand, an object can have constant velocity if its speed is constant and its
direction is also constant.