Wedges and Inclined Planes

Wedges and Inclined Planes
Hi, welcome to this video lesson about the mechanical advantage of wedges.

A wedge is what we call a “simple machine” as it has no moving parts but provides large amounts of mechanical advantage. As you are aware, the shape of a wedge is just a triangle, usually isosceles, so that the length of two sides are equal, like the example shown here. Sometimes objects called inclined planes are used to the same effect. Thankfully, finding the mechanical advantage to these two objects is relatively easy.

Take for example this wedge, it has a length of 10 units and a width of 4 units. The equation for finding mechanical advantage is MA = l/w [where l = length and w = width]

So, in this case, we’d divide 10/4 which equals 2.5. the mechanical advantage is 2.5.

Let’s try another. Here’s a wedge, it’s got a length of 21 units and a height of 3, what is the mechanical advantage of using it?

The answer? 7. Because 21/3 = 7.

Now, you may be wondering about inclined planes. Well, no worries, they work exactly the same as wedges, or at least the equation for their mechanical advantage does. Simply find the length of the tool and divide that by the height of the plane. Here’s an example where the length is 15 and the height is 5. The advantage is 15/5 which is 3.

Make sense? Here are a few practice problems to try by yourself.

A wedge is 14 inches in length, and the mechanical advantage is 7, what is the width of the tool?


A truck ramp is used for its mechanical advantage, if it’s 18 meters long and 3 meters high, what is the mechanical advantage of this inclined plane?


I hope that helps, thanks for watching this video tutorial.



by Mometrix Test Preparation | Last Updated: June 15, 2020