Worksheets and No Prep Teaching Resources
Worksheets and No Prep Teaching Resources
Reading Comprehension Worksheets
Forces and Motion
Push + Pull = Bridge?

Forces and Motion
Forces and Motion


Push + Pull = Bridge?
Print Push + Pull = Bridge? Reading Comprehension with Sixth Grade Work

Print Push + Pull = Bridge? Reading Comprehension

Reading Level
     edHelper's suggested reading level:   grades 6 to 7
     Flesch-Kincaid grade level:   6.44

Vocabulary
     challenging words:    cable-stayed, clapper, equalize, pontoon, standing, cantilever, foundation, span, suspension, compression, tidal, design, ideal, underside, posts, entire
     content words:    Ancient Romans, Golden Gate Bridge, San Francisco


Push + Pull = Bridge?
By Trista L. Pollard
  

1     You see them everywhere. When you travel on those long family vacations, you even cross a few of them. What are they? They are bridges. Bridges are structures that cross rivers and lakes. They are one of the earliest forms of architecture that have existed around the world. What makes these structures special is how they are able to support their weight and the weight of vehicles and people traveling across their spans. Why were bridges built, and what helps bridges to stand over running water?
 
2     Bridges were built for one practical reason -- to cross waterways to get to the other side. These structures which are elevated or raised must support their own weight and the weight of people and vehicles. There is a special set of forces that helps to accomplish this goal. Force is defined as the push or pull on objects. Compression and tension are the push and pull that help bridges to remain standing. Compression is a force that squeezes objects together. Think about the s'mores you made at camp last summer. After you combined the marshmallows, chocolate, and graham crackers, you squeezed everything together to make your ideal camp snack. Tension is the force that stretches or pulls objects apart. This is the opposite of compression. Compression and tension cause objects to become shorter or longer. If an object is being compressed (like your marshmallow), it becomes shorter. If an object is being pulled (like chewing gum), it is under tension and therefore becomes longer. Together, tension and compression balance to help structures like bridges remain standing. When the roadway of a bridge is being compressed, the underside of that roadway is in tension. If these forces are not balanced, the structure will become weak and may fall. Now, let's talk about bridges.
 
3     Bridges are designed to remain standing regardless of the changes in outside forces. These forces include high winds, tidal and river currents, and shifting in the earth's surface like earthquakes. Bridges are classified as three types: beam, arch, and suspension. Beams are horizontal pieces of wood, metal, or stone that are used for support. You usually see wooden beams in your floor at your home. They are held up by columns or posts. Beam bridges have a horizontal piece that stretches across a stream or ditch. The earliest and simplest form of a beam bridge could be a huge tree branch stretching across a small stream. The weight of the vehicles or people traveling on the bridge compresses or pushes down on the beam. As the top of the beam is pushed, the bottom of the beam is stretched or in tension. Beam bridges may also have larger beams called girders, piers, and trusses to give extra support. Trusses are frames made from beams that equalize tension and compression in a structure such as a bridge. Some examples of beam bridges are pontoon, clapper, cantilever, and cable-stayed bridges.

Paragraphs 4 to 6:
For the complete story with questions: click here for printable



Weekly Reading Books

          Create Weekly Reading Books

Prepare for an entire week at once!


Feedback on Push + Pull = Bridge?
Leave your feedback on Push + Pull = Bridge?  (use this link if you found an error in the story)



Forces and Motion
             Forces and Motion


Science
             Science


    Careers in Science  
 
    Caring for Earth  
 
    Clouds  
 
    Dinosaurs  
 
    Earth's Land  
 
    Earth  
 
    Earthquakes  
 
    Electricity  
 
    Energy  
 
    Erosion  
 
    Food Pyramid  
 
    Food Webs and Food Chain  
 
    Forces and Motion  
 
    Fossils  
 
    Health and Nutrition  
 
    How Things Work  
 
    Landforms  
 
    Life Science  
 
    Light  
 
    Magnets  
 
    Matter  
 
 
    Moon  
 
    Natural Disasters  
 
    Photosynthesis  
 
    Plant and Animal Cells  
 
    Plants  
 
    Rocks and Minerals  
 
    Science Process Skills  
 
    Scientific Notation  
 
    Seasons  
 
    Simple Machines  
 
    Soil  
 
    Solar System  
 
    Sound  
 
    Space and Stars  
 
    Sun  
 
    Tsunami  
 
    Volcanoes  
 
    Water Cycle  
 
    Water  
 
    Weather  
 



Copyright © 2017 edHelper