He set up mirrors on mountains that faced each other, 35 kilometers away. Then he calculated how long it took light to reflect off of the mirrors. Why did Michelson place the mirrors so far apart?
A) If the distance were shorter, there would not be enough time to measure the light as it bounced from one mirror to another
B) At a shorter distance, the intensity of the light would have been too bright for accurate measurement
C) Shorter distances affect the wavelength of visible light
D) At a shorter distance, the index of refraction would be too small to measure
A) If the distance were shorter, there would not be enough time to measure the light as it bounced from one mirror to another
B) At a shorter distance, the intensity of the light would have been too bright for accurate measurement
C) Shorter distances affect the wavelength of visible light
D) At a shorter distance, the index of refraction would be too small to measure
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The answer is A. Light travels at a speed of 300 million metres per second. 35 kilometers is just 35,000 metres. speed = distance/time
time = 35,000 / 300,000,000 = 1.16 x 10^-4 seconds. That is a tiny amount of time. Imagine making things worse by decreasing the distance between the two mirrors, measuring such a small amount of time is pretty much impossible.
B is wrong because solving an issue of intensity would be much more simply resolved by using a dimmer lamp than moving mirrors kilometers towards each other.
C is wrong because it is complete nonsense, distance has nothing to do with the wavelength of light, it will remain the same wavelength
D is wrong because for the same reason as B is. If the refractive index is too small, then just change the position/angle of the mirrors. There's no reason to move them kilometers closer to each other.
time = 35,000 / 300,000,000 = 1.16 x 10^-4 seconds. That is a tiny amount of time. Imagine making things worse by decreasing the distance between the two mirrors, measuring such a small amount of time is pretty much impossible.
B is wrong because solving an issue of intensity would be much more simply resolved by using a dimmer lamp than moving mirrors kilometers towards each other.
C is wrong because it is complete nonsense, distance has nothing to do with the wavelength of light, it will remain the same wavelength
D is wrong because for the same reason as B is. If the refractive index is too small, then just change the position/angle of the mirrors. There's no reason to move them kilometers closer to each other.
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Option A