It takes 4.3 seconds for the rocket to return to earth.
The equation is:
![0=-9.8t^2+v_0t+h_0](https://tex.z-dn.net/?f=0%3D-9.8t%5E2%2Bv_0t%2Bh_0)
where -9.8m/sec² is the acceleration due to gravity, v₀ is the initial velocity, and h₀ is the initial height. We will go from the assumption that the rocket is launched from the ground, so h₀=0, and we are told that the initial velocity, v₀, is 42. This gives us:
![0=-9.8t^2+42t](https://tex.z-dn.net/?f=0%3D-9.8t%5E2%2B42t)
We will use the quadratic formula to solve this. The quadratic formula is:
![x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cpm%20%5Csqrt%7Bb%5E2-4ac%7D%7D%7B2a%7D)
Plugging in our information we have:
![t=\frac{-42\pm \sqrt{42^2-4(-9.8)(0)}}{2(-9.8)} \\ \\=\frac{-42\pm \sqrt{1764-0}}{-19.6} \\ \\=\frac{-42\pm \sqrt{1764}}{-19.6} \\ \\=\frac{-42\pm 42}{-19.6}=\frac{-42-42}{-19.6} \text{ or } \frac{-42+42}{-19.6} \\ \\=\frac{-84}{-19.6}\text{ or }\frac{0}{-19.6} \\ \\=4.3\text{ or }0](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-42%5Cpm%20%5Csqrt%7B42%5E2-4%28-9.8%29%280%29%7D%7D%7B2%28-9.8%29%7D%0A%5C%5C%0A%5C%5C%3D%5Cfrac%7B-42%5Cpm%20%5Csqrt%7B1764-0%7D%7D%7B-19.6%7D%0A%5C%5C%0A%5C%5C%3D%5Cfrac%7B-42%5Cpm%20%5Csqrt%7B1764%7D%7D%7B-19.6%7D%0A%5C%5C%0A%5C%5C%3D%5Cfrac%7B-42%5Cpm%2042%7D%7B-19.6%7D%3D%5Cfrac%7B-42-42%7D%7B-19.6%7D%20%5Ctext%7B%20or%20%7D%20%5Cfrac%7B-42%2B42%7D%7B-19.6%7D%0A%5C%5C%0A%5C%5C%3D%5Cfrac%7B-84%7D%7B-19.6%7D%5Ctext%7B%20or%20%7D%5Cfrac%7B0%7D%7B-19.6%7D%0A%5C%5C%0A%5C%5C%3D4.3%5Ctext%7B%20or%20%7D0)
x=0 is when the rocket is launched; x=4.3 is when the rocket lands.
Answer:
The standard deviation will be: 2.1
Step-by-step explanation:
We know that standard deviation is basically the square root of variance.
Using the formula to calculate the standard deviation
![s=\sqrt{s^2}](https://tex.z-dn.net/?f=s%3D%5Csqrt%7Bs%5E2%7D)
As
so the standard deviation can be calculated as:
standard deviation ![=\sqrt{s^2}](https://tex.z-dn.net/?f=%3D%5Csqrt%7Bs%5E2%7D)
![=\sqrt{\left(4.4\right)^}](https://tex.z-dn.net/?f=%3D%5Csqrt%7B%5Cleft%284.4%5Cright%29%5E%7D)
![=2.1](https://tex.z-dn.net/?f=%3D2.1)
Therefore, the standard deviation will be: 2.1
Answer:
= 18x + 4y hope this helps :)
Step-by-step explanation:
-8t+6+6t=5t-2
-2t+6=5t-2
-2t-5t=-2-6
-7t=-8
-7 -7
T=1.14 or 1 1/7
Answer:
your answer is 20. Hope this helped! :)
Step-by-step explanation: