During first 50s of flight, rocket propelled straight up.  What is the average velocity of the rocket during the first 125ft? In t seconds its height s is s(t)=t^3/sqrt10  ft.

Expert Answers
beckden eNotes educator| Certified Educator

First we have to find the time it took the rocket to travel 125 ft.

`125ft = t^3/sqrt(10)` we get `t = root(3)(125sqrt(10)) = 5root(6)(10)` sec.

so the average velocity would be `(s(5root(6)(10))-s(0))/(5root(6)(10))`

`s(5root(6)(10))=125ft` , `s(0) = 0ft` , so

Average velocity = `125/(5root(6)(10))` = 85.1615 ft/sec