on mars, if you hit a baseball, the height of the ball at the time "t" would be modelled by the quadratic function....

Question

anonymous · Answer

$$h(t) = -1.85t ^{2} + 20t +1 $$
, where t is in seconds and h(t) is in metres. 

- when will the ball hit the ground?
-How long will the ball be above 17m?

anonymous · Answer

the ball will hit the ground after t=10.81 secs
the time taken to reach the maximum height is,5.41.
now put h(t)=17 and find the corresponding time t, say t1.
so the required time in the 2nd part is 2*(5.41-t1)