in this video we're going to look at how we can use scale drawings to find the resultant force on an object let's imagine that a man on his bike is peddling to create a force of 4 neutrons northwards at the same time though a strong breeze is blowing him eastwards with a force of 3 newtons we can represent this situation on a grid where the cyclist is this orange dot and the forces are shown as a four centimeter arrow upwards and a three centimeter arrow to the right so that each newton is equal to one centimeter now that we have a scale diagram we can find the magnitude and direction of the resultant force by placing these two vector arrows tip to tail which we could do by moving this one up here so that the tip of the north vector is just touching the tail of the east vector then to find the resultant force we just draw a line from the starting point over to the end point and because our drawing is the scale we can just measure it with a ruler to see how long it is in this case five centimeters and then we can convert that into neutrons using our scale so because each centimeter is one newton our resultant force would be five newtons to find the direction of the force we just measure this angle here with a protractor which would give us around 37 degrees so we could say that the resultant force is 5 newtons at a bearing of 37 degrees from north in some cases the forces might all balance in which case the object will be at equilibrium for example if we had a particle that had these three forces acting on it then to find the overall force we just arrange the three arrows tip to tail like before and because they all join up perfectly like this it means there must be zero resultant force don't worry about arranging the arrows in any particular order though as long as you put them all tip to tail then you'll be fine for example we could have arranged them like this instead they still form a perfect triangle which means there's no resultant force the last thing we need to look at is how to resolve vectors this is basically the opposite of what we've been doing so far in this video when you resolve a vector the aim is to split it up into its horizontal and vertical components and to do this in practice we need to use a scale drawing again let's imagine that we have a toy car and that we're exerting a force of 50 newtons on it to push it up the ramp how do we resolve this force well if we make our scale 10 newtons per centimeter then we could represent the 50 newton force with a 5 centimeter line at the same angle as the ramp then all we have to do is draw a horizontal line down here and a vertical line up here putting an arrow on each of them so that we know their directions then we just measure them with a ruler to find that they're four centimeters and three centimeters and so looking at our scale we can convert them to find that they must be a 40 newton force to the right and a 30 newton force upwards so we've now resolved the 50 newton force into its horizontal and vertical components that's everything for this video though so i hope you enjoyed it if you did then please do give us a like and subscribe and hopefully we'll see you again soon