The correct answer is (A). The speed of light would increase to a speed larger than the maximum speed of light in vacuum.
The index of refraction is the ratio of speed of light in vacuum to the speed of light in a medium.
n=C/V
here, n is the index of refraction, c the speed of light in vacuum, v is speed of light in any medium.
Now if the value of index of refraction is less than one, than the value of speed of light would be greater than the speed of light in the vacuum.
P (momentum) = mass x velocity
p = .5 x 20
p = 10
A control variable is the one element that is not changed throughout an experiment.A dependent variable is a variable whose variation does not depend on that of another.A independent variable is a variable whose value depends on that of another.