A person is swimming 1.1 m beneath the surface of the water in a swimming pool. A child standing on the diving board drops a ball into the pool directly above the swimmer. The swimmer sees the ball dropped from a height of 4.2 m above the water. From what height was the ball actually dropped?

The actual height is  

Explanation:

From the question we are told that

   The depth of the person is  

    The apparent height  is  

Generally

     The refractive index of water is  

      The refractive index of the air is  

The apparent depth is mathematically represented as

substituting values

=>  

compass can be used day and night, cloudy or sunny

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide