Determine the minimum length (in ft) of a sag vertical curve if the grades are −6 percent and +3 percent. design speed is 60 mi/h. consider the following criteria—stopping sight distance, comfort, and general appearance. (assume the perception-reaction time is 2.5 seconds, deceleration rate is 11.2 ft/s2, and the sight distance is less than the length of the curve.)

the inner core.

good luck: )

klicker

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.