10 Km.
S= Speed
D= distance
T= time
S= d/t
but since you are solving for "d" the equation is d=st so you plug in 10 km/h for speed and 2.1 hours for time and just multiply them. The hours cancel out so you are left with 10km.
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.
Answer:
I think the answer is D,54 joules
Answer:
we need to see the answers but probably 1 or -1
