 Hi, I'm Emmanuel. I am a current AMU student in my first year studying a Bachelor of Politics, Philosophy and Economics and a Bachelor of Arts, and I got involved with Mary Stone because I'm passionate about making accessible education videos for students around Australia. In this video, we're going to look at scalar and vector quantities. In science and maths, up until now, you've worked with numbers in units like 3 cm, 500 g and 17 seconds. These are called scalar quantities. In senior chemistry and physics, you're going to come across another type of quantity, the vector. So what are scalar and vector quantities? A scalar quantity is a quantity that has just a magnitude or a size. Some examples of scalar quantities include time, distance, mass, speed, temperature, volume and density. This is compared to a vector quantity which has both a magnitude and a direction which both need to be specified. Some examples of vector quantities include velocity, which is speed in a specific direction, acceleration, force, momentum and displacement. In order to understand the difference between scalar and vector quantities, we can look at an example. Say that we have a ball that is on a surface and we push it over to the right. Let's say that we push it five metres. We can then look at the distance of how far this ball has travelled and that is a scalar quantity and we can see that the ball has travelled five metres. In comparison, we can look at displacement which considers both the magnitude of how far the ball has travelled and in what direction and that is a vector quantity. We can say that the ball has travelled five metres to the right. So we can see the key difference between the scalar and vector quantity is that the vector quantity also includes the direction in which the ball has travelled, which is to the right. So those are the key differences between scalar and vector quantities which have a range of uses across the sciences.