Why is inclined plane important

For example:. A wagon trail on a steep hill will often traverse back and forth to reduce the gradient experienced by a team pulling a heavily loaded wagon. This same techique is used today in modern freeways which travel through steep mountain passes.

Some steep passes have separate truck routes that reduce the grade by winding along a separate path to rejoin the main route after a particularly steep section is past while smaller automobiles take the straighter steeper route with a resulting savings in time. The ramp or inclined plane was useful in building early stone edifices, in roads and aqueducts, and military assault of fortified positions.

Experiments with inclined planes helped early physicists such as Galileo Galilei quantify the behavior of nature with respect to gravity, mass, acceleration, etc. Detailed understanding of inclined planes and their use helped lead to the understanding of how vector quantities such as forces can be usefully decomposed and manipulated mathematically. This concept of superposition and decomposition is critical in many modern fields of science, engineering, and technology.

Other simple machines based on the inclined plane include the blade, in which two inclined planes placed back to back allow the two parts of the cut object to move apart using less force than would be needed to pull them apart in opposite directions. The diagram below shows how the force of gravity has been replaced by two components - a parallel and a perpendicular component of force.

The perpendicular component of the force of gravity is directed opposite the normal force and as such balances the normal force. The parallel component of the force of gravity is not balanced by any other force.

This object will subsequently accelerate down the inclined plane due to the presence of an unbalanced force. It is the parallel component of the force of gravity that causes this acceleration.

The parallel component of the force of gravity is the net force. The task of determining the magnitude of the two components of the force of gravity is a mere manner of using the equations.

The equations for the parallel and perpendicular components are:. In the absence of friction and other forces tension, applied, etc. This yields the equation. In the presence of friction or other forces applied force, tensional forces, etc.

Consider the diagram shown at the right. The perpendicular component of force still balances the normal force since objects do not accelerate perpendicular to the incline. Yet the frictional force must also be considered when determining the net force. As in all net force problems, the net force is the vector sum of all the forces. That is, all the individual forces are added together as vectors.

The perpendicular component and the normal force add to 0 N. The parallel component and the friction force add together to yield 5 N. The net force is 5 N, directed along the incline towards the floor.

The above problem and all inclined plane problems can be simplified through a useful trick known as "tilting the head. Thus, to transform the problem back into the form with which you are more comfortable, merely tilt your head in the same direction that the incline was tilted. Or better yet, merely tilt the page of paper a sure remedy for TNS - "tilted neck syndrome" or "taco neck syndrome" so that the surface no longer appears level. This is illustrated below. Once the force of gravity has been resolved into its two components and the inclined plane has been tilted, the problem should look very familiar.

Merely ignore the force of gravity since it has been replaced by its two components and solve for the net force and acceleration. Begin the above problem by finding the force of gravity acting upon the crate and the components of this force parallel and perpendicular to the incline. Now the normal force can be determined to be N it must balance the perpendicular component of the weight vector. The net force is the vector sum of all the forces. The forces directed perpendicular to the incline balance; the forces directed parallel to the incline do not balance.

The net force is N N - N. The acceleration is 2. For example, if you have a ramp with a slope length 20 meters that rises 5 meters high, then your trade-off is moving the 20 meters distance versus lifting straight up 5 meters, and your ideal mechanical advantage is 4. A screw is a simple machine that has two purposes.

It can be used to fasten two or more objects together or it can be used to lift up a heavy object. In most applications, a lever is used to turn the screw. A good example of this is a screwdriver. It is the circumference of the lever or screwdriver and the pitch of the screw that determines the mechanical advantage of the screw. The pitch of a screw is the distance between adjacent threads on that screw. The pitch can be calculated by dividing a certain distance by the number of threads on screw.

One complete revolution of the screw into an object is equal to the distance of the pitch of a screw. The ideal mechanical advantage of a screw is found approximately by dividing the circumference of the lever by the pitch of the screw. Today, we learned about two simple machines; the inclined plane and the screw. Who can give me an example of an inclined plane?

Possible answers: Ramp, staircase, escalator. How does an inclined plane help us do work? Possible answer: We push objects up an inclined plane.

What is the trade-off? Answer: Distance What are two ways screws are used? Answer: To fasten objects or to lift something. What other simple machine often helps us use a screw? Answer: A lever. What has an engineer designed that uses an inclined plane or a screw?

Possible answers: Parking garage, ramp, escalator, drilling rig, holding parts of something together, such as an airplane or MP3 player. In other lessons of this unit, students study each simple machine in more detail and see how each could be used as a tool to build a pyramid or a modern building. To deviate from the horizontal. Usually a straight slanted surface and no moving parts, such as a ramp, sloping road or stairs. Making the task easier which means it requires less force , but may require more time or room to work more distance, rope, etc.

For example, applying a smaller force over a longer distance to achieve the same effect as applying a large force over a small distance. The ratio of the output force exerted by a machine to the input force applied to it. Mesoamerica: A region extending south and east from central Mexico to include parts of Guatemala, Belize, Honduras and Nicaragua.

In pre-Columbian times it was inhabited by diverse civilizations, such as the Mayan and the Olmec. The typical shape is a square or rectangular base at the ground with sides faces in the form of four triangles that meet in a point at the top. Mesoamerican temples have stepped sides and a flat top surmounted by chambers.

Often a cylindrical rod incised with a spiral thread. For example, a wedge, wheel and axle, lever, inclined plane, screw, or pulley. The amount or degree of deviation from the horizontal.

On a large sheet of paper or on the classroom board, draw a chart with the title "Simple Machines: Inclined Planes and Screws. Fill out the K and W sections during the lesson introduction as facts and questions emerge.

Fill out the L section at the end of the lesson. List all of the things students learned about inclined planes and screws and their mechanical advantages. Were all of the W questions answered? What new things did they learn? Closing Discussion: Ask students to explain why it is easier to pull a cart or block up a long, shallow ramp than taking it up steps, a ladder or a steep ramp. Ask them to give examples of mechanical advantage using an inclined plane or a screw.

Bingo: Provide each student with a sheet of paper containing a list of the lesson vocabulary terms. Have each student walk around the room and find a student who can define one vocabulary term. Students must find a different student for each word.

When a student has all terms completed they shout "Bingo! Ask the students who shouted "Bingo! Using the Equations: Provide additional sample problems similar to the examples given in the Lesson Background for students to calculate themselves the mechanical advantage of an inclined plane and of a screw. Have them use the equations provided in the Lesson Background for the mechanical advantage of an inclined plane and a screw.

Investigation : Have students investigate balanced versus unbalanced forces on their own at home. Instruct them to follow these steps and answer the given questions:.

Have students build upon their understanding of inclined planes by discussing different uses for ramps. When might you add friction to make the ramp work better? Draw pictures of different ramps for different uses. How do they differ? Have students look at an assortment of different screws and calculate the mechanical advantage of each.

Which one has the greatest mechanical advantage, the least? Have them screw different fasteners into wood. Can you feel and see the difference in mechanical advantage of a screw that has close threads vs. Have students research Archimedes' screw and write a brief report describing how this device works, drawing sketches and providing their own examples of everyday ways it might be used to help people.

Henderson, Tom. The Physics Classroom a high school physics tutorial. Accessed January 25, Wright, Richard. Ladies and gentleman However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.

Why Teach Engineering in K? Find more at TeachEngineering. Quick Look. Simple Machines. Print this lesson Toggle Dropdown Print lesson and its associated curriculum. Suggest an edit.