Suppose a railroad rail is 3 kilometers and it expands on a hot day by 15 centimeters in length. approximately how many meters would the center of the rail rise above the ground?

 13.4 m

Step-by-step explanation:

For small angles, x, in radians,

tan(x) ≈ sin(x) = x

Use this to create an approximate diagram for the problem as shown in the figure below.

The actual deflected shape is parabolic, but it is approximated by an isosceles triangle with small equal angles.

The extend length is 3 km + 12 cm, which is 

3000 + 0.12 = 3000.12 m

Half of the extended length is 1500.06 m

Let h+  the rise of the center of the rail above ground.

From the Pythagorean theorem, obtain

h² + 1500² = 1500.6²

h² = 1500.06² - 1500² = 180.004

h = 13.4 m, which is about 0.9% of the original length.

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y=3x+4

step-by-step explanation:

given the points a(0,4) and b(-4, -8)

eqn of line ab: (y-4)/(x-0)=(-8-4)/(-4-0)

(y-4)/x=-12/-4=3

y=3x+4

i dont know

step-by-step explanation: