An inclined plane is one of the six simple machines that makes up all other machines, according to the Columbus Center of Science and Industry (COSI). An inclined plane is a flat surface sloped to reach between two points on different levels. Even though it has no moving parts, it is considered a machine because it is a tool that either multiplies or redirects force, according to Utah State University's Junior Engineering program. Though it doesn't change the amount of work (scientifically defined as force acting over distance) needed, it makes lifting an object from a low level to a higher point feel easier by spreading out the force or effort you need to exert over a longer distance. Wheel chair ramps and playground slides are two examples of an inclined plane.
- 2 pieces of 3/4 inch plywood, 2 by 3 feet
- 8-foot length of two-by-two lumber
- Circular saw
- Straight edge
- Wood screws, 1 1/2 inches
- Drill with bit slightly narrower than wood screws
Draw a line using your pencil and straight edge diagonally across one plywood rectangle. Cut with your circular saw to create two right triangles. Set aside.
Lay down your remaining plywood rectangle. Measure and mark 2 inches in from either side along one of the short ends. This will be the "top" of the inclined plane. Cut a piece of two-by-two that fits between the two marks. From the plywood side, drill and screw in the piece of two-by-two along the top edge of the rectangle, so it is between the two marks.
Lay out your right triangles. Cut a piece of two-by-two for each triangle so that it will fit along the edge of the slope, centered 2 to 3 inches from both acute angles. Drill holes along the edge of the slope from one side of the plywood through the two-by-two and screw it in so the edges are flush. Make sure the two-by-twos are installed on opposite sides of the plywood from one triangle to the other so both strips will be on the inside when the slope of the triangle is up and the edge with the 90-degree angle is down.
Support the two triangular sides, so they are standing with sloped sides up and the right-angle ends are in line with each other and spaced 2 feet apart. Lay the rectangular top on the sides so the top edge with the support is at the top of the slope. All edges should be flush.
Drill into the support at the top of the inclined plane from the top edge of each side of the triangle support sides. Secure with 1 1/2-inch wood screws.
Secure the top of the ramp to the triangular supports by drilling through the plywood top to the two-by-two supports inside the sloped edge of the triangular supports and attaching with 1-1/2-inch wood screws.
Tips & Warnings
- A partner will make supporting and securing the ramp easier.
- For a simpler inclined plane, just slope a piece of plywood, or other flat surface between your high point and the ground. The longer the slope, the less strenuous your work will feel, according to Utah State.