i have NOOOO idea how to solve this one problem:
A bridge is two miles long. In the heat of the summer the bridge surface expands two feet. Assume that the expansion is concentrated at the center of the bridge. How many feet high (from the old roadbed) is the center of the bridge after the expansion?
Please tell me how to do this!!
2007-10-07 12:47:44 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
It's a triangle.
One leg is 1 mile (that's to the middle of the bridge)
The hypotenuse is 1 mile + 1 foot
The roadbed is the other leg
change everything to feet
5280^2 + x^2 = 5281^2
x^2 = 10461
x = 102.7'
2007-10-07 12:59:45 · answer #1 · answered by Steve A 7 · 0⤊ 0⤋
Well you now have a triangle with base = 2miles and sides that both equal 1mile and 1 foot
So you have a right triangle that has a hypotenuse of 5,281 feet and a leg = 5,280 feet. The other le = sqrt(5281^2-5280^2) = 102.77 feet
2007-10-07 12:57:43 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋
are you sure this is an algebra question?
Using Pythagoras's theorem
1 mile = 5280 ft
so h^2 = 5281^2 - 5280^2 = 10561
h = 102.76 ft
2007-10-07 12:57:46 · answer #3 · answered by norman 7 · 0⤊ 0⤋