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cestrela7 [59]
4 years ago
5

if a toy rocket is launced vertically upward from ground level with an inital velocity of 128 feet per second, then its high h,

after t seconds is given by the equation h(t)=-9t^2 +81 round to the nearest foot when does the ball hit the ground?
Mathematics
1 answer:
makkiz [27]4 years ago
7 0
The toy rocket hits the ground when h(t) = 0.
So, h(t) = 0 = -9t^2 + 81.

Solving the equation,
-9t^2 = -81
Dividing by -9
t^2 = 9
Taking the square root.
t = 3

The answer is 3 seconds.
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What is the y-intercept of the equation of the line that is perpendicular to the line y = 3/5 x + 10 and passes through the poin
TiliK225 [7]

Answer:

\large\boxed{y-intercept=20}

Step-by-step explanation:

\text{Let}\ k:y=_1x+b_1\ \text{and}\ l:y=m_2x+b_2.\\\\l\ \perp\ k\iff m_1m_2=-1\to m_2=-\dfrac{1}{m_1}\\============================\\\\\text{We have}\ y=\dfrac{3}{5}x+10\to m_1=\dfrac{3}{5}.\\\\\text{Therefore}\ m_2=-\dfrac{1}{\frac{3}{5}}=-\dfrac{5}{3}.\\\\\text{The equation of the searched line:}\ y=-\dfrac{5}{3}x+b.\\\\\text{The line passes through }(15,\ -5).

\text{Put thecoordinates of the point to the equation.}\ x=15,\ y=-5:\\\\-5=-\dfrac{5}{3}(15)+b\\\\-5=(-5)(5)+b\\\\-5=-25+b\qquad\text{add 25 to both sides}\\\\b=20\\\\\boxed{y=-\dfrac{5}{3}x+20}

8 0
3 years ago
Pls help or i will fail
vladimir2022 [97]

Answer:

2926

Step-by-step explanation:

8 0
3 years ago
Distribute and simplify these radicals.<br> 712 (-1+5)
hjlf
Your answer would be 2848. Always do the equation in the parentheses first, so -1 + 5 is 4. So then you multiply 4 by 712. Hope this helped :)
4 0
3 years ago
Please help me please
Tamiku [17]

Answer:

(4,-3)

Step-by-step explanation:

is 4<3? no

is -2<3? yes but is 1>_ 8? no

etc etc

6 0
3 years ago
15000(1.07)^7 round to the nearest whole number
Anettt [7]
I think it’s 3, i input it all into my calculator. i’m not sure about the exponent tho so probably 3^29

3 0
3 years ago
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