Answer:
Step-by-step explanation:
B
Hello!
10 seconds to return to the ground.
7 seconds to reach 576 feet above the ground.
Find the amount of time taken to reach the ground by setting the equation equal to 0:
0 = -16t² + 80t + 800
Factor out -16 from the equation:
0 = -16(t² - 5t - 50)
Factor the terms inside of the parenthesis:
0 = -16(t - 10)(t + 5)
Find the zeros:
t - 10 = 0
t = 10
t + 5 = 0
t = -5
Time can only be positive in this instance, so the correct answer is 10 sec.
Find the time by substituting in 576 for the height:
576 = -16t² + 80t + 800
Subtract 800 from both sides:
-224 = -16t² + 80t
Rearrange:
0 = -16t² + 80t + 224
Simplify:
0 = -16(t² - 5t - 14)
0 = -16(t - 7)(t + 2)
t = 7 seconds.
Answer:
The answer to your question is:
x = -8; y = 1 ; z = -4
Step-by-step explanation:
Δ = ![\left[\begin{array}{ccc}-5&1&-4\\2&4&3\\6&-3&-2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-5%261%26-4%5C%5C2%264%263%5C%5C6%26-3%26-2%5Cend%7Barray%7D%5Cright%5D)
= 40 + 24 + 18 - (-4 + 45 - 96)
= 82 + 55
= 137
Δx = ![\left[\begin{array}{ccc}60&1&-4\\-12&4&3\\-52&-3&-2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D60%261%26-4%5C%5C-12%264%263%5C%5C-52%26-3%26-2%5Cend%7Barray%7D%5Cright%5D)
= - 480 - 144 - 156 - ( 24 - 540 + 832)
= -780 -316
= - 1096
Δy =
= 40 + 24 + 18 - ( - 4 + 45 - 96)
= 82 + 55
= 137
Δz = ![\left[\begin{array}{ccc}-5&1&60\\2&4&-12\\6&-3&-52\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-5%261%2660%5C%5C2%264%26-12%5C%5C6%26-3%26-52%5Cend%7Barray%7D%5Cright%5D)
= 1040 - 360 - 72 - ( - 104 - 180 + 1440)
= 608 - 1156
= -548
x = -1096/ 137 = -8
y = 137 / 137 = 1
z = -548 / 137 = -4
