Solar cells and solar panels are both integral, and closely related, parts of a solar energy system. When reading about solar energy systems, it may seem as if these titles are almost interchangeable. Writers refer to them both when discussing energy production and output, and often do so without explanation of how these parts work. However, each plays a distinct role. Solar cells contain all the parts necessary to convert sunlight to electricity. Solar panels combine and direct all of that energy output.
Answers A and C can be automatically eliminated because evaporation has to do with the water cycle and magnetism has to do with electric current and such. Next we can eliminate B or distillation because it also has to do with water/liquids. Therefore, the answer is D or filtration because it is the only answer left.
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Answer:
Part a)

part b)

Part c)

Part d)
here since wave is moving in negative direction so the sign of
must be positive
Explanation:
As we know that the speed of wave in string is given by

so we have


now we have


now we have
Part a)
= amplitude of wave

part b)

here we know that


so we have


Part c)

Part d)
here since wave is moving in negative direction so the sign of
must be positive
Replacement teeth were made even back then out of primitive materials, and pig hair was used like floss