Answer:
what's your question I can't understand
Look at the rock sitting on the hill in the picture above. Gravity should make the rock slide down the hill. What force is acting to balance gravity,keeping the rock in place? - D. friction
Centripetal force and momentum have to do with movement. Gravity cannot balance gravity.
Answer:
I just took the quiz and got 100% when choosing A.Conservation. Hope this helps:)
maximum speed of cheetah is

speed of gazelle is given as

Now the relative speed of Cheetah with respect to Gazelle


now the relative distance between Cheetah and Gazelle is given initially as "d"
now the time taken by Cheetah to catch the Gazelle is given as

so by rearranging the terms we can say


so above is the relation between all given variable