# Distinguish between speed and velocity Speed is a scalar quantity that refers to how fast an object is moving. It is defined as the distance traveled per unit of time, and it is measured in meters per second (m/s).

Velocity, on the other hand, is a vector quantity that refers to both the speed and the direction of an object’s motion. It is defined as the rate of change of an object’s position with respect to time. It is usually expressed as a combination of speed and direction, and it is measured in meters per second (m/s) in a specific direction.

To sum it up, speed is a measure of how fast an object is moving, regardless of its direction. Velocity is a measure of both the speed and direction of an object’s motion.

### How to calculate speed

To calculate speed, you need to know the distance traveled and the time it took to travel that distance. The formula for speed is:

speed = distance/time

For example, if a car travels a distance of 100 kilometers in 2 hours, its speed can be calculated as follows:

speed = 100 kilometers / 2 hours = 50 kilometers per hour

Note that the unit of time must be consistent with the unit of distance. In the example above, the distance is in kilometers and the time is in hours, so the speed is in kilometers per hour. If the distance were in miles and the time in hours, the speed would be in miles per hour.

### How to calculate velocity

To calculate velocity, you need to know the displacement of an object (the change in its position), and the time it took for the object to undergo that displacement. The formula for velocity is:

velocity = displacement/time

Displacement is a vector quantity that refers to the change in the position of an object, and it is equal to the final position minus the initial position of the object.

For example, if a car travels a distance of 100 kilometers to the east in 2 hours, its velocity can be calculated as follows:

velocity = (100 kilometers to the east) / 2 hours = 50 kilometers per hour to the east

Note that the unit of time must be consistent with the unit of displacement. In the example above, the displacement is in kilometers and the time is in hours, so the velocity is in kilometers per hour. If the displacement were in miles and the time in hours, the velocity would be in miles per hour.

It’s important to note that velocity is a vector quantity, which means it has both magnitude (size) and direction. In the example above, the magnitude of the velocity is 50 kilometers per hour, and the direction is to the east.

### Difference between speed and displacement

Speed is a scalar quantity that refers to how fast an object is moving. It is defined as the distance traveled per unit of time, and it is measured in meters per second (m/s).

Displacement is a vector quantity that refers to the change in the position of an object. It is equal to the final position minus the initial position of the object, and it is usually measured in meters (m).

The main difference between speed and displacement is that speed is a measure of how fast an object is moving, regardless of its direction, while displacement is a measure of the change in position of an object, taking into account its direction.

For example, if a car travels a distance of 100 kilometers to the east in 2 hours, its speed can be calculated as follows:

speed = distance / time = 100 kilometers / 2 hours = 50 kilometers per hour

The displacement of the car can be calculated as follows:

displacement = final position – initial position = (100 kilometers to the east) – (0 kilometers) = 100 kilometers to the east

As you can see, the speed of the car is 50 kilometers per hour, regardless of the direction of its motion, while the displacement of the car is 100 kilometers to the east, taking into account its direction.

### What are scalar and vector

A scalar is a quantity that is fully described by its magnitude (size) alone. It has no direction. Some examples of scalar quantities are mass, volume, temperature, and energy.

A vector is a quantity that is fully described by both its magnitude (size) and its direction. Some examples of vector quantities are velocity, acceleration, and force.

One way to remember the difference between scalars and vectors is to think of scalars as quantities that can be completely described by a single number, while vectors are quantities that require both a number and a direction to be fully described.

For example, the speed of an object is a scalar quantity because it only describes how fast the object is moving, regardless of its direction. On the other hand, velocity is a vector quantity because it describes both the speed and the direction of an object’s motion.