A 1000 kg car accelerates from rest at a rate of 10 m/s² for 3 seconds. A) what is the final velocity of the car?

Explanation:

We don't need the mass of the car in the equation to solve for final velocity, since the values given for the acceleration and the time it took to accelerate to that velocity are given. The equation we need is the one for acceleration, which is

We are solving for final velocity, we know the initial velocity is 0 (starting from rest), and the time to complete this acceleration (10 m/s/s) is 3 seconds:

which is the same thing as saying

so

v = 30 m/s

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.