A person dives from a 30-foot platform with an initial velocity of 5 feet per second (upward).

position function: s(t)=-16t^2+5t+30

How long will it take for the diver to hit the water?

Question

A person dives from a 30-foot platform with an initial velocity of 5 feet per second (upward).

position function: s(t)=-16t^2+5t+30

How long will it take for the diver to hit the water?

anonymous · Answer

:O You guys aren't seriously going to use this imperial crap when doing physics? Can't end well: -> http://en.wikipedia.org/wiki/Mars_Climate_Orbiter But seriously.. you already know the equation. You want to have the time (t). Just solve for it.... (do you know the quadratic formula?)

anonymous · Answer

oh crap i forgot about that formula. wow i'm so dumb -_- k lemme solve using that then i'll let you know if i'm right.

anonymous · Answer

i still didn't get it somehow...

anonymous · Answer

@MuH4hA

anonymous · Answer

Well - if you aren't going to tell what u did, ther's not much I can do to help...

anonymous · Answer

$$\frac{ 5\pm \sqrt{25-4(-16)(30)} }{ 10 }$$

anonymous · Answer

so far am i right?

anonymous · Answer

it's a negative 5 btw...

anonymous · Answer

uuups sry - totally overlooked this "thread".. sry...

Ahm - yes, it should be negative 5, but unfortunately your denominator is wrong. Please check that again.

anonymous · Answer

got it! Thanks! :D

anonymous · Answer

you're welcome :)