please solve right now

Answer:
45 mph
251 ft
Step-by-step explanation:
[tex] s = \sqrt{30fl} [/tex]
a.)
[tex] s = \sqrt{30(0.85)(80)} [/tex]
[tex] s = \sqrt{2040} [/tex]
[tex] s = 45 [/tex]
Answer: 45 mph
b.)
[tex] 80 = \sqrt{30(0.85)l} [/tex]
[tex] 80^2 = (\sqrt{25.5l})^2 [/tex]
[tex] 25.5l = 6400 [/tex]
[tex] l = 251 [/tex]
Answer: 251 ft