1. **State the problem:**
We have a toy rocket launched from a platform 48 feet high, with height modeled by the equation $$h = -16t^2 + 32t + 48$$ where $h$ is height in feet and $t$ is time in seconds.
2. **Part A: Find the height after 1 second.**
Substitute $t=1$ into the equation:
$$h = -16(1)^2 + 32(1) + 48$$
$$h = -16 + 32 + 48$$
$$h = 64$$
So, the height after 1 second is 64 feet.
3. **Part B: Find the time when the rocket reaches the ground.**
The rocket reaches the ground when $h=0$:
$$0 = -16t^2 + 32t + 48$$
Divide both sides by -16 to simplify:
$$0 = \cancel{-16}t^2 + \cancel{-16}\left(-2\right)t + \cancel{-16}\left(-3\right)$$
$$0 = t^2 - 2t - 3$$
Now solve the quadratic equation:
$$t = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a=1$, $b=-2$, $c=-3$.
Calculate the discriminant:
$$\sqrt{(-2)^2 - 4(1)(-3)} = \sqrt{4 + 12} = \sqrt{16} = 4$$
Find the roots:
$$t = \frac{2 \pm 4}{2}$$
Two solutions:
$$t = \frac{2 + 4}{2} = 3$$
$$t = \frac{2 - 4}{2} = -1$$
Since time cannot be negative, the rocket hits the ground at $t=3$ seconds.
**Final answers:**
- Part A: 64 feet
- Part B: 3 seconds
Rocket Height 90947D
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