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KIM [24]
4 years ago
5

The burning rates of two different solid-fuel propellants used in aircrew escape systems are being studied. It is known that bot

h propellants have the same standard deviation of burning rate; σ1 = σ2 = 3 centimetres per second. Two random samples of n1 = n2 = 20 are tested; the sample mean burning rates are 23.7 and 24 centimetres per second respectively. If you want to test the hypothesis that the burning rates of the 2 propellants are different, what is the value of zcalc? In computing zcalc, use the hypothesis test with respect to LaTeX: \mu1-\mu2 μ 1 − μ 2 . Please report your answer in 2 decimal places.
Physics
1 answer:
Katena32 [7]4 years ago
5 0

Answer: z_{\text{calc}}=-0.32

Explanation:

The test statistic for difference of two population means :-

z=\dfrac{\mu_1-\mu_2}{\sigma\sqrt{\dfrac{1}{n_1}+\dfrac{1}{n_2}}}

Given : \sigma=\sigma_1=\sigma_2=3

n_1 = n_2 = 20

\mu_1=23.7

\mu_2=24

Then , z=\dfrac{23.7-24}{(3)\sqrt{\dfrac{1}{20}+\dfrac{1}{20}}}

\Rightarrow\ z=-0.316227766017\approx-0.32

Hence, the value of z_{\text{calc}}=-0.32

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3 years ago
How much KCI can be dissolved in 100 g of water at 30°C?​
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Answer:

34

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3 years ago
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4 years ago
If you are lying down and stand up quickly, you can get dizzy or feel faint. This is because the blood vessels don't have time t
sammy [17]

Complete Question

If you are lying down and stand up quickly, you can get dizzy or feel faint. This is because the blood vessels don’t have time to expand to compensate for the blood pressure drop. If your brain is 0.4 m higher than your heart when you are standing, how much lower is your blood pressure at your brain than it is at your heart? The density of blood plasma is about 1025 kg/m3 and a typical maximum (systolic) pressure of the blood at the heart is 120 mm of Hg (= 0.16 atm = 16 kP = 1.6 × 104 N/m2).

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The pressure at the brain is P_b  = 89.872 \ mm \ of \ Hg

Explanation:

Generally is mathematically denoted as

                  P = \rho gh

Substituting 1025 kg/m^3 for \rho(the  density) , 9.8 m/s^2 for g (acceleration due to gravity) , 0.4m for h (the height )

We have that the pressure difference between the heart and the brain is

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But the pressure of blood at the heart is given as

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                     = 1.596*10^4 - 4018

                     = 11982 N/m^2

                      P_b= \frac{11982}{133} = 89.872 \ mm \ of \ Hg

   

     

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