 In this video we are going to go through the differences between distance and displacement, and how we might plot these out over time. But first we need to go through the difference between what is a scalar and what is a vector. Both a scalar and vector are types of measurement, however a scalar only tells you the magnitude or size of the measurement, whereas a vector will tell you both the magnitude and direction. There are a few cases where you might come across this. Whilst speed and distance are scalars, velocity and displacement are vectors, they also have a direction. Velocity therefore tells us how fast an object is moving as well as its direction. Displacement tells us how far an object has moved and the direction that it has moved in. For example, a dog travelling 10m in 5 seconds has a speed of 2m per second, but a velocity of 2m to the right. Sometimes we need to plot an object's journey over time. To do this we use displacement time graphs and velocity time graphs. Let's have a look at the displacement time graph. Notice how time goes on the horizontal x-axis at the bottom and the displacement goes on the vertical y-axis. Time nearly always goes on the x-axis and then what you're measuring, so the displacement in this case, goes on the y-axis. Now let's add information to our displacement time graph. Alice starts walking to Bob's. Travelling at a constant speed, this will create a diagonal line from the origin. If she walks slower, the line will be less steep, having a smaller gradient, because in the same amount of time she will travel less distance. If she walks faster, the line will be steeper. She then walks back home at the same speed, but this time she is walking away from Bob, so the line we draw must head in the opposite direction. We draw the line downwards, back towards the horizontal axis. When she gets back to the horizontal axis, this means she is back home. She has no displacement anymore. If Alice stands still at any point, time will increase, but her distance will not change. This will mean that we draw a straight line across the plot. Now it's your go. Can you draw this journey? Pause the video, give it a go and press play when you think you have the answer. Did you get it right? 50 meters in 50 seconds is this diagonal line, then 30 seconds and another 50 meters, then 100 seconds to walk all the way home again. Did you label your horizontal and vertical axes correctly with units? Fun fact, did you know that the average walking speed of a person varies from country to country? A survey found that some of the fastest walking countries include Germany and the Netherlands, while some of the slowest include China and Austria. I hope you now understand the difference between scalar and vectors and how to happily draw displacement time graphs. If you liked the video, give it a thumbs up and don't forget to subscribe, comment below if you have any questions. Why not check out our Fuse school app as well? Until next time.