Answer:
Hence, Grasshopper will land on the ground after 1.5 sec.
Explanation:
It s given that:
The height, in feet, of the grasshopper above the ground after t seconds is modeled by the function:

Now we are asked to find:
In how many seconds will the grasshopper land on the ground?
i.e. we have to find the value of t such that h(t)=0
i.e.

i.e. we need to find the roots of the given quadratic equation.
On solving the quadratic equation or plotting it's graph we could observe that the point where h(t)=0 are:

As time can't be negative hence we will consider:

Hence, grasshopper will land on the ground after 1.5 sec.