Answer: 3.675 seconds
Step-by-step explanation:
Hi, when the object hits the ground, h=0:
h=−16t^2+48.6t+37.5
0=−16t^2+48.6t+37.5
We have to apply the quadratic formula:
For: ax2+ bx + c
x =[ -b ± √b²-4ac] /2a
Replacing with the values given:
a=-16 ; b=48.6; c=37.5
x =[ -(48.6) ± √(-48.6)²-4(-16)37.5] /2(-16)
x = [ -48.6 ± √ 4,761.96] /-32
x = [ -48.6 ± 69] /-32
Positive:
x = [ -48.6 + 69] /-32 = -0.6375
Negative:
x = [ -48.6 - 69] /-32 = 3.675 seconds (seconds can't be negative)
Feel free to ask for more if needed or if you did not understand something.
Answer:
first option
Step-by-step explanation:
I don't know how to explain
Try 9:2 and 3:1 but I'm not sure if that's right or not
Billion gallons per day, because the independent quantity is volume of water in billion gallons and dependent quantity is time in days.

<h2>
Explanation:</h2>
The nth term of an arithmetic series (
) and the sum of an arithmetic series (Sum), for n terms, can be found as:
![a_{n}=a_{1}+d(n-1) \\ \\ Sum=\frac{n}{2}[2a_{1}+(n-1)d] \\ \\ \\ Where: \\ \\ a_{1}:First \ term \\ \\ d:Common \ difference \\ \\ n=Number \ of \ term](https://tex.z-dn.net/?f=a_%7Bn%7D%3Da_%7B1%7D%2Bd%28n-1%29%20%5C%5C%20%5C%5C%20Sum%3D%5Cfrac%7Bn%7D%7B2%7D%5B2a_%7B1%7D%2B%28n-1%29d%5D%20%5C%5C%20%5C%5C%20%5C%5C%20Where%3A%20%5C%5C%20%5C%5C%20a_%7B1%7D%3AFirst%20%5C%20term%20%5C%5C%20%5C%5C%20d%3ACommon%20%5C%20difference%20%5C%5C%20%5C%5C%20n%3DNumber%20%5C%20of%20%5C%20term)
So, in this exercise:
![a_{1}=a=9 \\ \\ d=4 \\ \\ n=16 \\ \\ \\ Sum=\frac{16}{2}[2(9)+(16-1)4] \\ \\ Sum=8[18+(15)4] \\ \\ Sum=8[18+60] \\ \\ Sum=8[78] \\ \\ \boxed{Sum=624}](https://tex.z-dn.net/?f=a_%7B1%7D%3Da%3D9%20%5C%5C%20%5C%5C%20d%3D4%20%5C%5C%20%5C%5C%20n%3D16%20%5C%5C%20%5C%5C%20%5C%5C%20Sum%3D%5Cfrac%7B16%7D%7B2%7D%5B2%289%29%2B%2816-1%294%5D%20%5C%5C%20%5C%5C%20Sum%3D8%5B18%2B%2815%294%5D%20%20%5C%5C%20%5C%5C%20Sum%3D8%5B18%2B60%5D%20%5C%5C%20%5C%5C%20Sum%3D8%5B78%5D%20%5C%5C%20%5C%5C%20%5Cboxed%7BSum%3D624%7D)
<h2>Learn more:</h2>
Missing numbers in triomino: brainly.com/question/10510270
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