this west indian manatee is an aquatic mammal. like amphibians and reptiles, mammals are tetrapods (vertabrates with four limbs). explain why manatees are considered tetrapods even though they lack hind limbs, and suggest traits that manatees likely share with leopards and other mammals. discuss how early memebers of the manatee lineage might have differed from tday's manatees

Manatees are considered tetrapods due to tetrapod ancestor.

Explanation:

Manatees are considered tetrapods even though they lack hind limbs because they are the descended of the tetrapod common ancestor. The oldest ancestors of manatees were pig-like, four-legged animal that lives on land and eats grass but when some of them start living in the water so with the passage of time their hind limbs disappear because there is no need of these legs in water. So due to link with the four-legged animal manatees are considered tetrapods.

the speed increase from w to x due to increased gravity force

the speed decreases from x to y due to decrease in gravity