Today, I would like to say a few words about productivity of study. I believe that productivity may be seen as similar to the concept of power in mechanics. Power is the rate of change of Workdone, ie, dW/dt. In physics, workdone is defined as W = F.d, where F refers to the amount of force (or the amount of effort put in), and d refers to the distance moved (the amount of material that's been absorbed or the amount of questions that have been done).Let us examine both cases.
Case 1:This is one of the conditions in order to porperly summon the elephant. Spend at least one whole day on a single question and waste A LOT of rough paper, and at the end of the day still have no idea how the hell to do it.This is a classic case where effort is significant yet distance moved is zero. W = F.0 = 0

Case 2:
Here is another classic case where the distance moved is negligible.
Careless mistakes. So many that you get frustrated and stop doing anything altogether.
Once again,
W = F.0 = 0
The above two situations are examples of when you just wish that Workdone = effort . effort

Case 3:
This is rather self explanatory.
Effort = 0
Therefore, distance = 0
Hence, W = 0

Case 4:
When you study outside hall/home and then try to study but end up somewhere else doing nothing.
Once again,
Effort = 0
Therefore, distance = 0
Hence, W = 0
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