Identify the varibles in the equation for determining the ideal mechanical advantage of a lever

In the case of a lever, the ideal mechanical advantage, or IMA, is the ratio of the length of the effort arm to the length of the load arm, or IMA = Le / Lr. The effort arm measures the distance from the force applied to the fulcrum, and the load arm measures the distance from the weight, or output force, to the fulcrum.

In the case of a wheel and axle, ideal mechanical advantage is the ratio of the radius of the wheel, R, to the radius of the axle, r. In short, IMA = R/r.

In the case of a pulley system, the ideal mechanical advantage is equal to the number of support strings, N. IMA = N. Alternatively, ideal mechanical advantage is equal to two times the number of movable pulleys.

In the case of an inclined plane, the ideal mechanical advantage is the ratio of the length traveled up the inclined plane, L, to the height difference, h. IMA = L/h.

In the case of a wedge, the ideal mechanical advantage is the ratio of the depth of penetration, L, to the length of the separation of wedged surfaces, t. IMA = L/t.

In the case of a screw, the mechanical advantage is the ratio of the circumference of the screw to the distance traveled after each revolution. In other words, IMA = 2*pi*L / P, where L is the radius of the screw and P is the distance traveled after each revolution.

The actual benefits of a simple machine when compared to its ideal mechanical advantage are reduced due to energy loss caused by friction. The efficiency measures how close a simple machine is to its ideal mechanical advantage. Efficiency is the ratio of the work supplied to the work put into the machine.

from almost the creation of the first true maps of the earth, people started seeing how continents would be able to fit together.   in particular, people noticed that south america fits almost exactly into africa.

you should be aware that while world maps were around early in the 1600’s and better defined by the end of the 1700’s, those maps were not ‘public’ but were treated as state secrets.   and so it was not till much later that the broader ‘science’ community had access to good quality and accurate world maps.

get the whole story here…

it is now known that most of the major continental masses can be fit together in a jigsaw process.   in fact we now know that the continents were indeed once all joined together as one land mass – the supercontinent of pangaea.

if you look at most world maps you will ponder how this is evidence, as the continents really don’t appear to ‘fit’ together very well.   what you need to understand is that the vast majority of maps are drawn using a map projection that has the north and south poles (which are points) are a line the width of the map at the top and bottom.   this means that the map distorts the true shape of the earth’s land and oceans as you love closer to the poles.     some other map projections distort less, but have the map shape looking like segments of an orange.   see here for a range of map projections.   check out the way greenland changes size in each!

what is more remarkable, is the next piece of evidence when added to the shape of continents.

location of mountains and fossils

what is remarkable, when you reassemble all the continents together, the ancient mountain ranges (many now eroded to their cores) and the location of rock types and fossils all match up.

picture a world where computers are building made-to-order personalized robotic arms and synthetic organs, drones are circulating above mars! due to the rapid growth of technology, the future has never been more unpredictable, and it presents a huge challenge in education: we are teaching students how to work in a future that we have never been unsure of. it is widely predicted that in eight years’ time, there will be more jobs in the fields of science, mathematics, technology and engineering than in any other discipline. and, as the technology continues to develop, it will soon become clear that addressing social problems will involve more innovative thinking, and analytical and technical knowledge than ever before. undeniably, there are no subjects that encourage innovative and creative thinking, deep thought, problem solving and independence more than the stem subjects. while it is widely commented on that there is a need to reimagine the ways stem subjects are taught in schools by embracing a more interactive and innovative approach to appeal to more students, it should come as no surprise that some of the most reputable educational organizations in the world are already implementing changes to embrace stem. harvard, for example, announced in 2014 that they were increasing their computer science faculty by over 50% and has since introduced computer science as a core subject for all freshmen. the urgency of supporting stem subjects at a young age is becoming more relevant than ever, as adopting a keen interest in the curricula needs to happen early. however, beyond the age issue is one of gender.

let me know if you need more