Hello!
First, let's write some important information contained in the exercise:
• t = 0 (launching)
,
• h(t) = -4.9t² +250t +122
A)
We can solve it as a quadratic equation, equaling it to 0:

Let's find the coefficients:
• a = -4.9
,
• b = 250
,
• c = 122
Now, let's replace the values in the quadratic formula:
![\begin{gathered} x=\frac{-b\pm\sqrt[]{b^2-4\cdot a\cdot c}}{2\cdot a} \\ \\ x=\frac{-250\pm\sqrt[]{250^2-4\cdot(-4.9)\cdot122}}{2\cdot(-4.9)} \\ \\ x=\frac{-250\pm\sqrt[]{62500^{}+2391.2}}{-9.8} \\ \\ x=\frac{-250\pm\sqrt[]{64891.2}}{-9.8} \\ \\ x=(-250\pm254.7)/(-9.8) \\ \\ x^(\prime)=(-250-254.7)/(-9.8)=(-504.7)/(-9.8)=51.5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ip0rvus3hmvq2gczjltcbq6k3d5g8aoy0v.png)
Note: We don't need to calculate x'' because it will be negative, and we don't have a negative time.
B)
As the coefficient A is negative, it means that the concavity of the parabola will be facing downwards and this function will have a maximum point. So, let's use the formula below to obtain the height:

Answers:
The rocket splashes after 51.5 seconds.
The rocket peaks at 6,576.73 meters above sea level.