if an object is thrown vertically upward with an initial velocity of v, from an original position of s, the height h at any time is given by h=-16t^2 + vt + s (h and s are in ft, t is in seconds, and v is in ft/sec)

if a rock is thrown upward from a height of 100 ft, with an initial velocity of 32 ft/sec, solve for the time that it takes for it to hit the ground..
Round your answer to 2 decimals.

Question

if an object is thrown vertically upward with an initial velocity of v, from an original position of s, the height h at any time is given by h=-16t^2 + vt + s (h and s are in ft, t is in seconds, and v is in ft/sec) 

if a rock is thrown upward from a height of 100 ft, with an initial velocity of 32 ft/sec, solve for the time that it takes for it to hit the ground..
Round your answer to 2 decimals.

anonymous · Answer

So you got your height s = 100 ft 

you have a velocity.. v = 32 ft/sec

so your h(t) = -16t^2 +32t + 100

right? Did you do this part?

anonymous · Answer

All you need to do is factor using the quadratic formula...

$$x1, x2=\frac{ -b \pm \sqrt{b ^{2}-4ac} }{ 2a }$$

a = -16 b = 32 c = 100

Take the + root... if they are both positive use your discretion....Take the larger number root.