Answer: C- ecosystem
An ecosystem is a biological community in which living beings interacts with their non-living environment. An ecosystem consists of abiotic ( non-living factors like water, sunlight, wind and soil) and biotic factors such as plants and animals. Ecosystem allows not only the interaction of abiotic and biotic factors but it favors the interaction between the living species. For example animals are dependent upon plants so as to derive their food. The coexistence of organisms favors the diversity of land forms on earth.
Communities of organisms coexist in organized, balanced ecosystems.
Answer : The final energy of the system if the initial energy was 2000 J is, 3500 J
Solution :
(1) The equation used is,

where,
= final internal energy
= initial internal energy
q = heat energy
w = work done
(2) The known variables are, q, w and 
initial internal energy =
= 2000 J
heat energy = q = 1000 J
work done = w = 500 J
(3) Now plug the numbers into the equation, we get

(4) By solving the terms, we get




(5) Therefore, the final energy of the system if the initial energy was 2000 J is, 3500 J
Answer:
The answer is (a.) An upward force balances the downward force gravity on the skydiver
The skydiver is falling at a constant velocity because the upward force is balancing the downward force of gravity. According to Newton, the opposite force balance each other. This is stated in Newton's second law of motion.
Answer:
0.000003782 m
0.000001891 m
0.000001197125 m
Explanation:
= Wavelength = 248 nm
D = Diameter of beam = 1 cm
f = Focal length = 0.625 cm
The angle is given by

The width is given by

The required width is 0.000003782 m
Minimum resolvable line separation is given by

The minimum resolvable line separation between adjacent lines is 0.000001891 m
when 

The new minimum resolvable line separation between adjacent lines is

A nuclear power plant doesn't produce any of those things. It only produces electricity and heat. As long as there are no accidents, and the worn out nuclear fuel is handled properly, the nuclear plant isn't harmful to the environment at all.