What kind of organism is a zooxanthellae

It is a photosynthetic algae contained in reef building corals underwater

 zooxanthellae is a kind of organisms categorized under phylum Dianoflagellata.they are microscopic flagellated protozoans.they do photosynthesis.they live in aquatic or terrestrial environments or on other organisms like other protozoans or on other sea creatures symbiotically.(they provide the host with organic food synthesised by photosynthesis and host provide them the attachment,protection etc) 

When the ball is rising up, it gains kinetic energy. when the ball reaches the very top, it will have all potential energy, until it falls back down and gains it kinetic energy. finally when you catch the ball or it falls back down, it would have gained its potential energy back.