Beginning Algebra, 11th Edition

Solve each problem. Give answers to the nearest tenth.

73.To estimate the speed at which a car was

traveling at the time of an accident, a police

officer drives the car under conditions sim-

ilar to those during which the accident took

place and then skids to a stop. If the car is

driven at 30 mph, then the speed sat the time

of the accident is given by

where ais the length of the skid marks left at the time of the accident and pis the length

of the skid marks in the police test. Find sfor the following values of aand p.

(a) ; (b) ; (c) ;

74.A formula for calculating the distance done can see

from an airplane to the horizon on a clear day is

where xis the altitude of the plane in feet and dis

given in miles. How far can one see to the horizon

in a plane flying at the following altitudes?

(a)15,000 ft (b)18,000 ft (c) 24,000 ft

On a clear day, the maximum distance in kilometers that you can see from a tall building is

given by the formula

(Source: A Sourcebook of Applications of School Mathematics,NCTM, 1980.)

Use the conversion equations and as necessary to

solve each problem. Round your answers to the nearest mile.

75.As mentioned in the chapter opener, the

London Eye is a unique form of a Ferris

wheel that features 32 observation capsules

and has a diameter of 135 m. (Source:

http://www.londoneye.com) Does the formula jus-

tify the claim that on a clear day passengers

on the London Eye can see Windsor Castle,

25 mi away?

76.The Empire State Building in New York City is 1250 ft high. (The antenna reaches to

1454 ft.) The observation deck, located on the 102nd floor, is at a height of 1050 ft.

(Source:www.esbnyc.com) How far could you see on a clear day from the observation

deck?

77.The twin Petronas Towers in Kuala Lumpur, Malaysia, are 1483 ft high (including the

spires). (Source: World Almanac and Book of Facts.) How far would one of the builders

have been able to see on a clear day from the top of a spire?

1 ftL0.3048 m 1 kmL0.621371 mi

sight distance=111.7 2 height of building in kilometers.

d=1.22 2 x,

a=862 ftp=156 ft a=382 ftp=96 ft a=84 ft p=26 ft

s= 30

B

a

p

,

538 CHAPTER 8 Roots and Radicals

x

d

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