The function of ...?

Question

h(t)=-1.96t^2+10t+0.5 models the height of the mass of a rock, so when did the mass hit the surface of the lake?

Answer 1

The h(t) function sounds like it tells the height at time t, so you should let h(t)=0, and calculate t, looking for a positive value.

The answer is approximately 5.1516, presumably in seconds.

Answer 2

let t = 0

Answer 3

not enough info