A plane travels at a speed of 180 mph in still air. flying with a tailwind, the plane is clocked over a distance of 700 miles. flying against a headwind, it takes 2 hours longer to complete the return trip. what was the wind velocity?

Round this value however you need to

Explanation:

w = speed of the wind

The plane travels at a speed of 180 mph in still air. With a tailwind, the plane speeds up (the wind is coming from the tail to push the plane forward more), so the plane is now traveling at a speed of 180+w miles per hour. It travels 700 miles

d = r*t

700 = (180+w)*t

t = 700/(180+w)

This is the time it takes when the wind speeds up the plane.

In contrast, the headwind slows the plane down because now the wind is going against the plane. Headwinds attack the head of the plane and push against the plane. With a headwind, the plane is now going 180-w miles per hour. It travels for 2 hours longer to do the return trip (of 700 miles), so,

d = r*t

700 = (180-w)*(t+2)

700 = 180t + 360 - w*t - 2w

700 = 180( 700/(180+w) ) + 360 - w*( 700/(180+w) ) - 2w

700 = 126000/(180+w) + 360 - 700w/(180+w) - 2w

700(180+w) = 126000 + 360(180+w) - 700w - 2w(180+w)

126000+700w = 126000+64800+360w-700w-360w-2w^2

126000+700w = -2w^2 - 700w + 190800

-2w^2 - 700w + 190800 = 126000+700w

-2w^2 - 700w + 190800 - 126000-700w = 0

-2w^2 - 1400w + 64800 = 0

Use a graphing calculator or the quadratic formula to find the approximate solutions are

w = -743.5733730831, w = 43.57337308309

Ignore the negative value as it makes no sense to have a negative wind speed.

The only practical answer is approximately 43.57337308309 mph

this story was prepared by jim

mccullaugh in los angeles and

al stewart in new york.

new york the colossal success of "top gun" appears to have dramatically altered madison avenue's

perception of corporate sponsorship

of home video projects.

the paramount home video re- lease, featuring a 60- second diet

pepsi spot, was by no means the

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first major theatrical release to do so. in the aftermath of the title's

success, paramount is widely ex- pected to ink a similar deal for

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corporate america's new attraccds push british

recording sales

to 19% gain

london fueled by the compact

disk boom, the value of u.k. manu- facturer shipments of recordings

rose 19% in the 12 -month period ended march 1987, according to the

british phonographic industry.

total value of u.k. shipments for

the period was $755 million for all

configurations. (all value figures

are based on an exchange rate of

$1.68 to the pound sterling.)

cd sales totaled 10.7 million units

worth $121.3 million- compared

with 3.7 million units worth $39.5

million in the prior 12 months -and

accounted for two -thirds of the

overall gain in trade value. at present growth rates, says the bpi, cd

sales for calendar 1987 will reach 20

(continued on page 79)

step-by-step explanation: