If the direction of the whole course is straight, the average speed and the average velocity will be equal.ġ. So, if the displacement from point A to point D is only 5 km east, and it took an hour to get there, regardless of the 100 km travel distance, the average velocity is only 5 km/h east. In this case, the average velocity is also zero. A zero displacement can even occur when the destination came back to the origin. Thus, the average velocity can be very minimal. The direct distance (displacement) from A to D could well be very small. Here is the formula of the average velocity of traveling from A to D:Īverage Velocity = Displacement from A to D / Total time taken to get from A to D The formula is very similar to that of average speed, but instead of the total distance covered, it is supplanted by displacement. The displacement does not care about the distance of the whole course, as it only deals with the direct distance from the origin to the destination. The main difference is the factor used in the calculation, and that is the ‘Displacement’. This is possible due to the different way of calculating the average velocity. Average speed can reach an enormous value, while the average velocity may be very minimal, even zero. Average speed doesn’t care about the displacement from the origin, only the total distance covered to get to the destination.Ĭonsider this equation when trying to calculate the average speed of traveling from points A to D:Īverage Speed = (Distance from A to B + Distance from B to C + Distance from C to D) / Total time taken to get from A to DĪssuming that the total distance traveled is 100 km, and it took 1 hour to get there, the average speed is 100 km/hĪverage Velocity is totally different, not to mention that it is a vector quantity (with direction). Note that the traveling directions can go east, then west, zigzag, or back and forth the destination point can even go back to the starting point. A car from point A reaching an exact point B will have an average speed by adding all the distance covered divided by how long it took to get there. Average speed is all about the total distance traveled divided by the total time taken.
Once again, when you refer to speed, it is not a vector expression, therefore no direction is involved. Then again, don’t get intimidated, as it is quite easy when you get the grasp of it. In average speeds and average velocities, the direction may change and the speeds may vary, therefore, the calculations may somehow become a bit more complex. Well, that was quite easy just add a direction and voila! Instant conversion. We are all taught that when a car is moving forward, and has reached its destination at a straight distance of 10 km, in a time of 1 hour, then the speed will be 10 km/h, and the velocity will be 10 km/h north, assuming, that you are indeed going northwards. When it comes to traveling, average speed and average velocity will often differ, and perhaps by large quantities. If you think that both measurements will usually give the similar values, then, you’re wrong. However, I’m pretty sure that when you are asked about the difference between average speed and average velocity, you can’t actually elaborate more than the scalar and the vector aspects. Yes, most of us know that the first one is scalar and the latter is a vector quantity. Thus, we go into the world of speed and velocity. However, one should consider that scientists, engineers, and physicists need to differentiate terms for a more accurate experimentation and data analysis.
Physics definitely has a way of making things difficult, at least for the common mind.