Explain force velocity and duration of contraction?

The power produced by a muscle relies upon the quantity of Actin and myosin cross-spans shaped; a bigger number of cross-spans bring about a bigger measure of power. The cross-connect arrangement isn't quick and if my filaments slide over one another at a quicker rate, their capacity to frame cross-extensions and consequent power are both decreased.  

At a most extreme speed, no cross-extensions can frame so no power is created, bringing about the generation of zero power. The invert is valid for extending of muscle; in spite of the fact that the power of the muscle is expanded, there is no speed of compression and zero power is produced.  

The greatest power is created at roughly 33% of the most extreme shortening speed. The tug compressions are short in the span. Despite the fact that they have high speed, they start resting before arriving at pinnacle power. Tetanic withdrawals, which are long in term, arrive at pinnacle power and level.

i think that d. wind is the answer.   i missed the question when i answered a. currents.