If I have a force like this, if I have a force like this and it is acting at anĪngle theta right over here, with the horizontal, and I want to break it And to do so, we just have to remember a little bit of our basic trigonometry. So what I want to do is I want to break up this new blue force into its horizontal and vertical components. 'Cause if you leave it in this angle, it gets very, very confusing. And some other component is going to be working horizontally. To have a larger normal force to counteract that. Vertical components, some part of that force So if we were to break it up into its horizontal and But we would have to watch out because this force is acting at an angle. To just draw the force right on one of these free-body diagrams, something like that, something like that, and So what would the free-bodyĭiagram now look like? Well, it might be tempting The magnitude of this force is equal to 20 newtons. And just so that we know the direction, this angle right over here, let's say that that is 60 degrees. It's in this direction, and its magnitude, let's say its magnitude is 20 newtons. I am going to apply a force that is in this direction. But now I'm going to apply a force to it. So I have my surface here, my hard, frictionless Now, what I want to do is do something interesting to this block. This is another way that you might see free-body diagrams drawn. Have ten newtons downward, and you would have ten newtons upward. And from the outside of the body, you see the vectors being drawn. Might see it is like this, where you see the body. Now, I mentioned that there's other ways to draw a free-body diagram. No net force in total, and this thing isn't And I have no forces, I haven't thought about any or drawn any in the horizontal direction. Two are going to net out, and so you have no net force acting in this vertical dimension. Magnitude right over here, is also going to be equal to 10 newtons, but it's going upwards. The exact same magnitude, just in the opposite direction. So it's going to be going upwards, and it's going to have That surface is what's keeping the block from accelerating downwards. There's the normal force of this surface acting on the block. But I just said that this is not accelerating in any direction. Would happen to the object? Well, it would start or it would be accelerating downwards. Now, my question to you is, is that the only force acting on this? If you think it is, what Your vectors originating out of the center of that, of that object in your drawing. And when you draw a free-body diagram, it's typical to show It has a magnitude of 10 newtons, and the force is acting downwards. Newtons right over here, we know that there is a downward force, the force of gravity acting on the mass of The weight of an object, that's the force of gravityĪcting on that object, and it would be downwards. Now, I told you that it weighs 10 newtons. And there's actually two typical ways of drawing a free-body diagram. And we don't drawĮverything else around it, and we just draw the forces acting on it. And the reason why it'sĬalled a free-body diagram is that we just focus on this one body. And to do it, I'm going to draw what's known as a free-body diagram to think about all of the forces. So my question to you is, pause this video, and thinkĪbout what are all of the forces that are acting on this block? All right, now let's work And on that, I have a block, and that block is notĪccelerating in any direction. That's my drawing of a hard,įlat, frictionless surface. We have some type of hard, flat, frictionless

Mastering physics body diagrams