# Ideal mechanical advantage. And ramps.

Ramps are cool.  By extending the distance outwards, we can push things up to the same height if we were to lift it, but it is easier. By extending the distance, the work still remains the same, but since the distance is longer now, that means we put in less force. And now for mechanical advantage. Mechanical advantage (or MA for short) is how much more easier it is to do something compared to doing it without the machine. So if you had to push a block up a ramp, and the ramp had a mechanical advantage of 2, then the block would be 2x easier to push up the ramp, then just lifting the block to the same height as the ramp. For more on this, I will leave a link at the bottom which will take you to another page talking about mechanical advantage.

Anyway,let’s do a practice problem! So we have a box full of stuff. And it is heavy. So we make a inclined plane for it. We want to lift this box 5 feet in the air, but now we have a ramp that is 30 ft long. So if we calculate the MA, which is the length over the height, we get MA=6. So our mechanical advantage is equal to 6 right?  Well, no. It gets more confusing. The MA isn’t 6, the IMA is 6. It turns out, that there is two types of mechanical advantages. Ideal mechanical advantage (IMA) and actual mechanical advantage (AMA). Today, I will be talking about IMA and maybe in a later blog post I’ll talk about AMA .

Ok, so what does Ideal actually mean? Well the dictionary definition of ideal is – something that we want to happen, but won’t actually happen in reality. So in short it means to imagine a perfect world with no blemishes.

So, in our last practice problem we got 6 for IMA, but why is it IMA? Well, in the problem we are imagining a world where there is no air resistance and friction. In this ideal world, the only factor here is the box and the ramp. However, in the real world, there is something called friction. This will slow down the box, meaning that the AMA isn’t 6 but actually the AMA <6. So basically, the IMA what the MA would be in a world that doesn’t have any other factors except for the machine and the load.

How to calculate IMA.

IMA is basically the length of the ramp/ the height for a ramp/incline plane. IMA = L / H for a ramp. However, IMA doesn’t only apply to ramps. Levers also have IMA formulas, and so do all other simple machines. For levers it is the effort arm length over the resistance/load  arm length.