The pinned nail.
There is a nail. It was pinned to the 5-centimeter-thick board. The nail is 10-centimeter long. So that, another part of the nail outside the board is 5-centimeter-thick (picture above).
If you want to take the nail out, you need to apply a force F=1000N in order to move the nail. Also , the force F will be decrease if lenght of the nail inside the board increase, too.
How much derived unit of energy do you need to take the nail out (calculate in Joule)
The answer is 75.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
For the first 5 cm the force is 1000N, the work 50 J. For the next 5 cm, the force to pull out decreases form 1000N to 0N, since the portion of nail to be pulled decreases from 5 cm to 0 cm. so average force will be (1000 + 0)/2 N distance is 5 cm =work 25 J.
50 + 25 = 75 J