Black holes are thought to be abundant, yet they are hard to find. Explain why
What will be an ideal response?
Black holes are gravitational vacuums, so much so that light cannot escape. Consequently, they are really difficult to see (hence, "black hole"). In order to look for them, we must look for hot matter emitting x-rays as it is being engulfed by a black hole. In and of itself, this means that we can only look for black holes that are not isolated, as we need to be able to detect whatever matter is near them as it is being sucked in in order to determine the location of a black hole.
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The reason that temperature increases with altitude through most of the stratosphere is ________
A) greenhouse gases warm the air B) heat is released by absorption of UV radiation by oxygen and ozone C) sunlight is more intense in the stratosphere D) water vapor levels are high and store heat E) jet stream winds produce frictional heat
What type of reaction occurs when fumarate is converted to malate in step 7 of the citric acid cycle?
A) dehydration B) hydration C) oxidation D) reduction
Warm oceanic pools form in areas of
A. descending, stable air where much latent heat is released. B. warm water is forced to the surface due to upwelling. C. rising, unstable air where much latent heat is released. D. thermoclines near the surface when the sun is closer to the earth.
When a flood crest passes downstream, stream level falls more rapidly than it rose.
Answer the following statement true (T) or false (F)