A450-kg sports car accelerates from rest to 100 km/h in 4.80 s. what magnitude force does a 68.0 kg passenger experience during the acceleration?

We use the first equation of motion, to calculate the acceleration of the car

Here, v is final velocity and its value is 100 km/h = 100(1000/3600)  =  27 .78 m/s  and u is initial velocity as car accelerates from rest so its value zero and t is time taken and its value is given 4.80 s.

Therefore,

.

Now the magnitude of force,

.

Thus, the magnitude of force by passenger experience during the acceleration is 393 .52 \ N.

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.