(20 points) The cables of a suspension bridge are in the shape of a​ parabola, as shown in the figure. The towers supporting the cable are 300 feet apart and 20 feet high. If the cables touch the road surface midway between the​ towers, what is the height of the cable at a point 75 feet from the center of the​ bridge?  

What is the total amount of filtration required in x-ray machines operating over 70 kVp?

How does filtration affect the primary beam?

What is the primary function of filtration?

Secondary radiation barriers usually require ____.

How much lead equivalent must be placed in the protective curtain of fluoroscopic units?

What is the genetically significant dose (GSD) in the United States?

NOUNS. Provide the plural of each article and noun. Write one word per blank. These are the codes for typing accented characters on a PC. Uppercase Letters À: ALT + 0192 È: ALT + 0200 É: ALT + 0201 Ì: ALT + 0204 Ò: ALT + 0210 Ù: ALT + 0217 Lowercase Letters à: ALT + 0224 è: ALT + 0232 é: ALT + 0233 ì: ALT + 0236 ò: ALT + 0242 ù: ALT + 0249 For MAC users: Grave accent (`)  à, è, ì, ò, ù: Hold Option, press the ` key (next to the 1 on your keyboard), then release and press the letter. Acute accent (‘)  á, é, í, ó, ú: Hold Option, press the “e” key, then release and press the letter.

WRITING. Answer the following questions.  (Provide complete sentences to earn full credit!) These are the codes for typing accented characters on a PC. Uppercase Letters À: ALT + 0192 È: ALT + 0200 É: ALT + 0201 Ì: ALT + 0204 Ò: ALT + 0210 Ù: ALT + 0217 Lowercase Letters à: ALT + 0224 è: ALT + 0232 é: ALT + 0233 ì: ALT + 0236 ò: ALT + 0242 ù: ALT + 0249 For MAC users: Grave accent (`)  à, è, ì, ò, ù: Hold Option, press the ` key (next to the 1 on your keyboard), then release and press the letter. Acute accent (‘)  á, é, í, ó, ú: Hold Option, press the “e” key, then release and press the letter.

Any wall that the useful x-ray beam can be directed toward is called a ____.