A batter hits a pop fly straight up. (a) Is the acceleration of the ball on the way up different from its acceleration on the way down? (b) Is the acceleration of the ball at the top of its flight different from its acceleration just before it lands?

a) No. If air resistance is ignored the acceleration of the ball is the same at each point on its flight.

(b). No. As long as the air resistance is negligible, the acceleration of the ball at the top of its flight different from its acceleration just before it lands.

Explanation:

This constant, similar acceleration is called the acceleration due to gravity and it is the acceleration of a body due to the influence of the pull of gravity alone.

Every object on the surface of the earth regardless of its mass is pulled towards the centre of the earth, especially when in flight. Whether flying upwards, or coming downwards, the pull of attraction towards the surface of the earth is the same!

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.

b

explanation: