Leslie is speeding up to merge with traffic. When she begins to speed up, she has a velocity of 7.0 m/s west. When she merges with traffic 7.0 seconds later, she is traveling 23 m/s. Assuming east to be the positive direction, what is Leslie’s average rate of acceleration during this period? Select one:

a.2.3 m/s ^{2}

b.1.9 m/s ^{2}

c. -1.9 m/s ^{2}

d.-2.3 m/s ^{2}

seeing the graph would

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.

490 n

f=125n a=2.5m/s2