professional is the answer
3rd
Answer: it depends on the mass of the pendulum or on the size of the arc through which it swings.
Explanation:
A: the type of plant
B: how tall the plant is
see
below
Explanation:
refractive index = speed of light in vacuum / speed of light in medium
light travels at a speed of 3.0 x 10^8 m/s in vacuum
refractive index = 3.0 x 10^8 / 2.0 x 10^8
refractive index = 1.5
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