A car is driving across a street. It's change in displacement is 50 m. If it started with a velocity of 5 m/s and ended with a velocity of 7 m/s, what must the acceleration have been?

Ew an sao fan. anyway, it's 0.24m/s^2

Explanation:

Use this equation for 1 dimensional motion with constant acceleration:

Xf = Xi + Vi*T + 0.5A*T^2

Xf is 50 m when Xi is 0m

Vi is 5m/s

A is (7m/s-5m/s)/T = 2m/s/T

So,

50m = 0m + 5m/s *T + 0.5*2m/s/T * T^2

50m = 5m/s * T + 1m/s * T

50m = 6m/s * T

T = 8.33s

A is 2m/s/T

A is 2m/s/8.33s

A is 0.24m/s^2

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.