GROWTH DEVELOPMENT CHILD
SUMMATIVE ASSESSMENT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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They produce more red light than nearby galaxies
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They are moving away from us
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The longer wavelengths are filtered out more by dust
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They are moving toward us
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Detailed explanation-1: -Redshift is an example of the Doppler Effect. As an object moves away from us, the sound or light waves emitted by the object are stretched out, which makes them have a lower pitch and moves them towards the red end of the electromagnetic spectrum, where light has a longer wavelength.
Detailed explanation-2: -Red-shift and speed It is a result of the space between the Earth and the galaxies expanding. This expansion stretches out the light waves during their journey to us, shifting them towards the red end of the spectrum. The more red-shifted the light from a galaxy is, the faster the galaxy is moving away from Earth.
Detailed explanation-3: -The Doppler red-shift of light observed from distant stars and galaxies gives evidence that the universe is expanding (moving away from a central point). This allows for Big Bang Theory, because after a “bang” occurs all of the matter moves away from the point of origin.
Detailed explanation-4: -Hubble’s law explains that the reason most galaxies are moving away from one another is because the whole universe is expanding. Pick any two galaxies at random, and the chances are they’re moving away from each other.
Detailed explanation-5: -The wavelength of light emitted by an object is changed by its motion relative to an observer. An object moving away from us is ‘redshifted’ – that is, its light is shifted towards the longer wavelengths at the red end of the visible spectrum. But although the Universe is expanding, not all objects are redshifted.