When we calculate the average speed we see that it is 100km/h. At the end of the trip, if we want to learn average speed of the car we divide total distance to total time the trip takes.ДЄssume that car travels 500 km in a 5 hour. For example, a car moving with a constant speed travels to another city, it must stop at red lights in the traffic, or it should slow down when unwanted situations occur in the road. At a given instant time what we read from the speedometer is instantaneous speed. Sometimes it speeds up and sometimes slows down. We show with this example that speed and velocity are not the same thing.ДЄ moving object does not have the same speed during its travel. Speed = total distance/time of travel = 81m / 27s = 3m/s For example, we can symbolize the change in position as ?X.Д®xample Calculate the speed and velocity of the man moving 45m to the north, and 36m to the south in 27 seconds.ДЇirst we should calculate distance traveled and displacement of the man to calculate speed and velocity.

We use ? symbol to show the change in something.

In other words, if the displacement is zero we can not talk about the velocity.Д«e careful!! There must be a change in the position of the object to have a velocity. If a man walks 5m to east and then 5m to west speed of that man calculated by dividing total distance traveled which is 10m to the time elapsed, however, velocity calculated by dividing the displacement to the elapsed time, which is 0m divided elapsed time gives us zero. While we calculate speed we look at the total distance, however, in calculating velocity we must consider the direction and in short we can just look at the change in position not the whole distance traveled. We can define velocity as the вЂњrate of change of displacementвЂќ whereas вЂњthe speed is rate of change of distanceвЂќ. In daily life we use speed and velocity interchangeably but in physics they have different meanings. As you can understand from the definition velocity is a vector quantity having both magnitude and direction. Velocity can be defined as вЂњspeed having directionвЂќ. In my examples and explanations I will use m/s as a unit.Д®xample Calculate the speed of the car that travels 450m in 9 seconds. Motor vehicles commonly use kilometer per hour (km/h) as a unit of speed however in short distances we can use meter per second (m/s) as a unit of speed. I think itвЂ™s time to talk a little bit the units of speed. Let me formulate what we talk above ДЇrom the above formula we can say that speed is directly proportional to the distance and inversely proportional to the time. Speed does not show us the direction of the motion it just gives the magnitude of what distance taken in a given time. In daily life we use the first definition and say the faster object has higher speed.

Speed can be defined as вЂњhow fast something movesвЂќ or it can be explained more scientifically as вЂњthe distance covered in a unit of timeвЂќ.

Speed is a scalar quantity with just concerning the magnitude and velocity is a vector quantity that must consider both magnitude and direction.

In the same way we can categorize speed and velocity. Distance is a scalar quantity and displacement is a vector quantity. As mentioned in last section distance and displacement are different terms. Beyond the definition s of these concepts we will try to explain speed and velocity terms. In the last sections we have learned scalar and vector concepts. Speed velocity average and instantaneous speed and velocity with examples

Average speed symbol