An OBject projected from a height of 48ft with an initial velocity of 32ft per sec after t seconds has height.

h=-16t+32t+48

(a) after how many seconds is the height 64ft?
(b) After how many seconds is the height 60ft?
(c) After how many seconds does the object hit the ground?
(d) The quadratic equation from part (c) has two solutions, yet only one of them is appropriate for answering the question. Why?

Question

An OBject projected from a height of 48ft with an initial velocity of 32ft per sec after t seconds has height. 

h=-16t+32t+48 

(a) after how many seconds is the height 64ft? 
(b) After how many seconds is the height 60ft? 
(c) After how many seconds does the object hit the ground? 
(d) The quadratic equation from part (c) has two solutions, yet only one of them is appropriate for answering the question. Why?

anonymous · Answer

I am assuming that for the first term you meant -16^2...
a) sub in 64 for h, and solve for t
b) do the same with 60
c) In this, you assume height is 0...
d) Can time be negative?