Answer: C solar energy
Solar energy has the greatest impact on primary productivity.
Explanation:
Primary productivity is the amount of organic compounds synthesized from carbon dioxide. Primary production occurs by the process of photosynthesis. Since the process of photosynthesis uses sunlight as the energy source solar energy has the greatest impact on primary productivity.
The synthesis can occur in atmosphere as well as aquatic environment. The organisms that perform the function of primary production are called producers .In terrestrial regions plants are the producers and in aquatic systems algae are the primary producers.
Answer:
a) 
b) 
Explanation:
The frequency of the 
harmonic of a vibrating string of length <em>L, </em>linear density 
under a tension <em>T</em> is given by the formula:
a) So for the <em>fundamental mode</em> (n=1) we have, substituting our values:
b) The <em>frequency difference</em> between successive modes is the fundamental frequency, since:
I'm quite certain the answer is "stress".
