What force (size and direction) must exert the hand of a ball-thrower on the ball with m = 7,25 kg, so that it accelerates evenly on a 1,7 m long 42 ° rising distance, so that after leaving the hand in 2 m above the ground and 0.5 m before the start of the test, a throw of 18 m? calculate with g = 10 m / s2.

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.