Help me with these? Not sure how 2 do them.
11. If an object is dropped from a height of 144 ft, the function h(t) = –16t² + 144 gives the height of the object after t seconds. When will the object hit the ground? (1 point)1.5 s
3 s
6 s
9 s

12. A ball is thrown into the air with an upward velocity of 28 ft/s. Its height (h) in feet after t seconds is given by the function h = –16t² + 28t + 7. How long does it take the ball to reach its maximum height? What is the ball’s maximum height? Round to the nearest hundredth, if necessary. (1 point)1.75 s; 7 ft
0.88 s; 43.75 ft
0.88 s; 1

Question

Help me with these? Not sure how 2 do them.
11.   If an object is dropped from a height of 144 ft, the function h(t) = –16t² + 144 gives the height of the object after t seconds. When will the object hit the ground?  (1 point)1.5 s
3 s
6 s
9 s

12.   A ball is thrown into the air with an upward velocity of 28 ft/s. Its height (h) in feet after t seconds is given by the function h = –16t² + 28t + 7. How long does it take the ball to reach its maximum height? What is the ball’s maximum height? Round to the nearest hundredth, if necessary.  (1 point)1.75 s; 7 ft
0.88 s; 43.75 ft
0.88 s; 1

anonymous · Answer

@amistre64

anonymous · Answer

sorry i g2g

cwrw238 · Answer

11.

just plug in 144 for h(t)  and solve for t

amistre64 · Answer

and the min or max of a parabola is at its vertex ...

anonymous · Answer

11: u shold only solve this equation 144 = 16t^2 and the answer will be 3s
12: u should solve this equation -32t+28 = 0 and th answer will be .88 s it means when time = 0.88(S) u have the highest h(t) and that will be about 43