A piece of blue paper appears blue because the paper absorbs all colors of light except blue. <em> (b)</em>
So any light that bounces off of the paper and enters your eye must be blue light !
Answer:
red shift, indicating that the universe is expanding
Explanation:
Doppler effect occurs when a source of a wave (e.g. light, or sound waves) moves relative to an observer; as a result of this relative motion, the wavelength of the wave appears lengthened/shortened to the observer. Two situations can occur:
- The source of the wave is moving towards the observer - in this case, the wavelength of the wave becomes shorter. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the blue-end of the spectrum (blue-shift)
- The source of the wave is moving away from the observer - in this case, the wavelength of the wave becomes longer. If the wave is visible light, such as the light emitted by distant galaxies, this means that the wavelength of the light shifts towards the red-end of the spectrum (red-shift)
In our universe, we observe a red-shift for all the distant galaxies: this means that these galaxies are moving away from us, so this is an indication that the universe is expanding.
Answer:
221754385964.9123
Explanation:
Convert miles to nanometer
1 mile = 1.6 km
1 km = 1×10³×10³×10³×10³ nm
1 mile = 1.6×10¹² nm
So,
158 miles = 158×1.6×10¹² = 252.8×10¹² nm
Length of each molecule = 1140 nm
Number of molecules = Total length / Length of each molecule
There are 221754385964.9123 number of molecules in a stretch of 158 miles
Explanation:
speeds = distance/time
=100/16
=6.25m/s
second speed is;
400/44 =9.09
av. speed = total speed /n
= (6.25+9.09)/2
=7.67 m/s
