With what minimum speed must you toss a 200 g ball straight up to just touch the 12-m-high roof of the gymnasium if you release the ball 1.4 m above the ground? solve this problem using energy. express your answer to two significant figures and include the appropriate units.

v = 14.41 m/s

Explanation:

It is given that,

mass of the ball, m = 200 g = 0.2 kg

Height of the roof, h = 12 m

The ball is tossed 1.4 m above the ground, h' = 1.4 m

Let v is the minimum speed with which the ball is tossed. Using the conservation of energy to find it as :

v = 14.41 m/s

So, the minimum speed with which the ball is thrown straight up is 14.41 m/s. Hence, this is the required solution.

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.