Hey guys, we are going to start introducing a little bit about physics, what it is, and the difference between scalar and vector. All right, so first off, just what is physics? Well physics is basically the science of matter and its motion. So it deals with concepts like force, energy, mass, charge, magnetism. As an experimental science, the whole goal is to understand our natural world. We are trying to describe a complex universe with some very simple clarifying laws. All right, so I know you have probably heard the term scalar and vector before. Scalar is basically just the magnitude of a particular quantity. So like your speedometer or what determines your speed on your car, that is just giving you the magnitude of your travel, the meters per second there. You can add and subtract scalar quantities just using simple algebraic rules. Okay? All right, now velocity is a little different. velocity has a magnitude and a direction. That means that we cannot add or subtract them algebraically. We have to break them down into x and y components, resultant vectors, and analyze them in that way using trigonometry. All right, so we are talking about describing a vector in terms of directions. There are a bunch of methods that can be employed. Primarily in our class, we are going to use two different methods. We are either going to use the x, y coordinate system. Where in this system, basically to the top of your x axis, that is going to be all your positive y directions and then below, this is all going to be your negative. And then in terms of the x, it is going to be based on where it is located in a reference to your y axis. So positive x's are over here and then the negative x direction is over there. The other way we might describe motion is with our compass headings. So you got North, East, South, and West. So I remember this as never eat soggy waffles. And we are always going to describe the direction in relation to another reference point. So we might say, North East of the horizon or something to that effect. Okay, so I threw up a couple of words that we are going to look at while we are in this unit, which is called kinematics. Okay. All right, so we are just going to go through all these words and we are going to label them as vector or scalar. All right. So position, believe it or not, is a vector quantity. That means it has magnitude and position. Acceleration also a vector quantity. So we are going to have both magnitude and direction speed. This is going to be a scalar quantity. Velocity is the vector quantity. Distance again, a scalar quantity. Lacement is a vector quantity. And last but not least, force is another vector quantity.