On some ziplines, stopping at the bottom is also controlled by friction. The riders are given gloves so that as they near the end of the line, they can slide their hand on the line to slow themselves down. The force between the hand and the line is an example of friction at work. Air resistance is another force working to slow you down on the zipline. A lot of factors go into the air resistance that you experience while traveling down the line.
Check out this science behind ziplines. As high pressure systems work up valleys this increases air resistance for zipliners. This complicated equation can be explained by three things: the surface area of the traveling object, the speed of that object on the line, and some constants including air density and drag.
The faster an object is traveling, the more air resistance it will experience. When the air resistance reaches a certain point, that is when the object reaches terminal velocity: the maximum speed of travel for that object in those conditions.
Air resistance is always acting against the direction of travel, so you may notice your speed leveling out as you get further down the line. The key difference in the science behind zipline travel for a heavier person compared to a lighter one involves air resistance and terminal velocity. You may notice that the air resistance equation above says nothing about the mass of the traveling object.
The air resistance experienced does not depend on how heavy the object is. The start point is 13 m above the ground and the end point is 11 m above the ground. Both points have been securely anchored using trees. Notice that the topography of the ground has a slightly downward grade from the start point to the end point. There is an elevation drop of 12 m. This helps achieve a sufficient slope, approximately 4 degrees in this example, without causing the cable to be extremely high off the ground at the start point.
For safety reasons, a weight range of 70 to pounds is acceptable for a zip line this size. Home Science Behind Zip Lining. Design of a Zip Line Every zip line consists of a trolley attached to a steel cable that is typically covered with a vinyl coating. Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts.
Websites for research:. After teaching the Unit, present the evidence below that growth in learning was measured through one of the instruments identified above. Show results of assessment data that prove growth in learning occurred. Also, most student comments were positive about their learning experiences. I will use all four activities again for this unit.
Math Units. CEEMS is funded by the National Science Foundation, grant Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
Date: June The Big Idea including global relevance Human Safety Zip lines have been used for many years to transport goods and individuals across remotely accessible terrain. The Essential Question What factors contribute to the safety and enjoyment of zip line rides?
ACS Real world applications; career connections; societal impact A real world Application — In this unit, students will investigate zip line systems. Engineering Design Process The engineering design process is introduced in Activity 1 as students in teams work through the engineering design process to design and construct a zip line structure that will deliver a ball into a cargo box.
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