In your own words, explain what a black hole is and how it forms by integrating the information from the two sources.

A black hole is a region of spacetime where gravity is so strong that nothing, including particles and electromagnetic waves such as light, can escape.

Thus, that's how formation of a black hole happens.

Learn more about black hole, here

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According to the General Theory of Relativity, a black hole is a region of space from which nothing, not even particles that move at the speed of light, can escape because their velocity is less than the escape velocity of these infinitely dense celestial bodies . This is the result of the deformation of space-time, caused after the gravitational collapse of a massive star with at least 30 times the mass of the Sun in a supernova, and that soon after, will disappear, giving place to what Physics calls singularity, the heart of a black hole, where space-time ceases to exist. A black hole starts from a spherical surface called the event horizon, which marks the region from which, if something to cross, can not return. The black adjective in black hole is due to the fact that it was assumed that it did not reflect any part of the light that reaches its horizon of events, acting as if it were a perfect black body in thermodynamics, however, there is currently the theory of radiation Hawking, who briefly predicts that black holes are not really black, and emit radiation due to quantum effects such as quantum fluctuations.

1. read the following excerpt from franklin d. roosevelt's "fireside chat 19":

on the other side of the picture, we must learn also to know that guerilla warfare against the germans in, let us say serbia or norway, us; that a successful russian offensive against the germans us; and that british successes on land or sea in any part of the world strengthen our hands.

remember always that germany and italy, regardless of any formal declaration of war, consider themselves at war with the united states at this moment just as much as they consider themselves at war with britain or russia. and germany puts all the other republics of the americas into the same category of enemies. the people of our sister republics of this hemisphere can be honored by that fact.  

the true goal we seek is far above and beyond the ugly field of battle. when we resort to force, as now we must, we are determined that this force shall be directed toward ultimate good as well as against immediate evil. we americans are not destroyers — we are builders.

analyze the effectiveness of this excerpt. how does it function within the speech as a whole? how does the structure of the excerpt to convey the speech's purpose and key points? support your argument with evidence from the speech. (10 points)