Example of work done
Previous picture is a young man climbing stairs. He does this 4 seconds (Hint: it's me!). Minimum energy that he had done can be calculated by potential energy when he reaches the top.
The potential energy is equal to 1455.3 J. Because this energy was exerted over a time interval of 4 seconds, the work value is 363.8 W, or .488 horsepower.
Another example of work done
Picking up a 15 lb (6.81kg) a height of 4 meters in 1 second.
PE/t = 267.0W = .358hp
An example of work not being done analogous to the second example would be holding the object still at 4 meters over a time interval. Over that time interval, no energy is neither gained nor lost. Therefore, no work is done.
Overall, I enjoyed looking at your blog. It isn't too overwhelming and it is neatly organized. If I had to give a suggestion I would say expanding upon the last thought you have in here about an example of work not being done. The explanation is sufficient, however, a picture or maybe even a calculation would be helpful for the readers understanding. One question I have is did you skip a step when you were climbing up or did you do one step at a time? Because, skipping a step would explain the speedy four second time! Overall, great blog, I appreciated the humor.
ReplyDeleteI greatly appreciate the diagram of the stairs as it is very helpful. I enjoyed reading and the simple format of this blog. I think the last example of work not being done could be elaborated on perhaps using a picture or diagram to explicitly illustrate that point. I would ask you the methodology of climbing the stairs as to how much effort was put in to achieve the four second time?
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