Radar works by sending out electromagnetic energy at a particular wavelength and receiving a reflected signal from distant objects, similar to a sound echo. Many modern military aircraft have what is known as “stealth technology” that allows the aircraft to be invisible to enemy radar. What statement best explains how this is possible? A. The coating on the aircraft is highly reflective.

B. The coating on the aircraft absorbs incoming light energy.

C. The aircraft is extremely fast, allowing it to outrun the enemy radar.

D. The aircraft has a very rounded shape that refracts incoming light energy.

The correct option is B

Explanation:

Ordinary aircrafts are coated with materials that are highly reflective; reflecting incoming electromagnetic signal/wave/energy back to the radar antenna. The round shape of ordinary aircrafts also does the same thing. However, stealth technology uses coatings that absorbs radiated energy (instead of reflecting it) and converts it to heat. It also changes the rounded shape of aircrafts into flat surfaces with very sharp edges which reflects waves in directions away from the radar antenna.

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)