The answer to this question is A.
Answer:
READ THIS FIRST!!!
I am not going to right the parragraph (it says to use your own words, they could trace it back to me if you use my words, and you would get it trouble).
But I will tell you the forces acting on the pencil:
Gravity (pulls on the pencil)
Your hand (pushing it up canceling out gravity)
And the electromagnetic force (holding the thing together)
Hope it helped,
Have a good day
Using the 3rd equation of motion:
= v² - u² = 2gs ------ [g = Acceleration due to gravity]
= v² - 20² = 2 × 10 × 300
= v² - 400 = 6000
= v² = 6000 - 400
= v = √5600
= v = 74.83 m/s
And yeah it's done :)
Yes, light enters your eye and makes things visible. It's only a small portion of the elctromagnetic spectrum. It's called "visible light." What other things does the question want to know? I could go in a describe what light really is but I think itd be unnecessary.
It is potential energy because the band is not in movement, th band has the potential to move.