Suppose a railroad rail is 3 kilometers and it expands on a hot day by 20 centimeters in length. approximately how many meters would the center of the rail rise above the ground

Center of the rail rise above the ground in 17 m.

Solution:

The railroad rail is 3 km = 3000 meter

It expands 20 cm = 0.2 meter on hot day in length

So it will form a triangle with base 3000 m and the equal sides will be

Let us assume that the center of the rail will raise x meter.

So using Pythagoras theorem,  

Taking square roots on both sides we get,

So, the rail raise 17 meter from the ground .

24 units

step-by-step explanation:

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15