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2 years ago

Almost all collisions are due to driver error

Engineering

1 answer:

blondinia [14]2 years ago

4 0

Answer:

Where's the questaion?

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George and Ellen Rottweiler encourage their adult daughter Guinevere to break her engagement and continue living in their home,

Andrew [12]

Answer:

Negative feedback

Explanation:

In Biology, negative feedback refers to the counteraction of an effect by its own influence on the process producing it. For instance, the presence of a high level of a particular hormone in the blood may inhibit further secretion of that hormone.

In other words, in negative feedback, the result of a certain action may inhibit further performance of that action

7 0

3 years ago

A 25-W compact fluorescent lightbulb (CFL) produces the light equivalent of a 100-W incandescent bulb. The population of North A

wariber [46]

Answer:

Coal required is 101 Teragram/year.

Coal saved is 25.25 Teragram/year.

Explanation:

1 Teragram is exactly 1000000000 kilograms.

8 0

3 years ago

6.32 LAB: Exact change - functions

Neko [114]

Answer:

Below is the desired C++ program for the problem. Do feel free to edit it according to your preference

Explanation:

#include <iostream>

#include <vector>

using namespace std;

void ExactChange(int userTotal, vector<int> &coinVals) {

coinVals.reserve(5);

coinVals[0] = userTotal / 100;

userTotal %= 100;

coinVals[1] = userTotal / 25;

userTotal %= 25;

coinVals[2] = userTotal / 10;

userTotal %= 10;

coinVals[3] = userTotal / 5;

userTotal %= 5;

coinVals[4] = userTotal;

}

int main() {

vector<int> coins;

int value;

cin >> value;

if (value <= 0) {

cout << "no change" << endl;

} else {

ExactChange(value, coins);

if (coins[0] != 0) cout << coins[0] << " " << (coins[0] == 1 ? "dollar" : "dollars") << endl;

if (coins[1] != 0) cout << coins[1] << " " << (coins[1] == 1 ? "quarter" : "quarters") << endl;

if (coins[2] != 0) cout << coins[2] << " " << (coins[2] == 1 ? "dime" : "dimes") << endl;

if (coins[3] != 0) cout << coins[3] << " " << (coins[3] == 1 ? "nickel" : "nickels") << endl;

if (coins[4] != 0) cout << coins[4] << " " << (coins[4] == 1 ? "penny" : "pennies") << endl;

}

return 0;

}

5 0

3 years ago

The force on a cutting tool are 2600N vertically downward and 2100 horizontal. Determine the resultant force acting on the tool

kolezko [41]

Answer & Explanation:

"The force <em>on a cutting tool</em> are 2600N vertically downward" sounds a little unusual, since most of the time, the tool is above the object to be cut in such a way that the force acting "ON the tool" is upwards. We will accept the statement as it is (downwards).

Since the two forces are acting at right angles to each other, the resultant can be found using Pythagoras theorem, namely

resultant = sqrt(2600^2+2100^2) = 3342 N (approx.)

The angle can be found using the arcTangent function, or

angle = arcTangent(2600/2100) = 51.07 degrees below the horizontal, since the 2600 N force is acting downwards.

3 0

3 years ago

A square aluminum plate 5 mm thick and 150 mm on a side is heated while vertically suspended in quiescent air at 75°c. determine

Doss [256]

By using the boundary layer equation, the average heat transfer coefficient for the plate is equal to 4.87 W/m²k.

<u>Given the following data:</u>

Surface temperature = 15°C

Bulk temperature = 75°C

Side length of plate = 150 mm to m = 0.15 meter.

<h3>How to calculate the average heat transfer coefficient.</h3>

Since we have a quiescent room air and a uniform pole surface temperature, the film temperature is given by:

$T_f=\frac{T_{s} + T_{\infty} }{2} \\\\T_f=\frac{15 + 75 }{2} \\\\T_f = 45$

Film temperature = 45°C to K = 273 + 45 = 318 K.

For the coefficient of thermal expansion, we have:

$\beta =\frac{1}{T_f} \\\\\beta =\frac{1}{318}$

From table A-9, the properties of air at a pressure of 1 atm and temperature of 45°C are:

Kinematic viscosity, v = $1.750 \times 10^{-5}$ m²/s.

Thermal conductivity, k = 0.02699 W/mk.

Thermal diffusivity, α = $2.416 \times 10^{-5}$ m²/s.

Prandtl number, Pr = 0.7241.

Next, we would solve for the Rayleigh number to enable us determine the heat transfer coefficient by using the boundary layer equations:

$R_{aL}=\frac{g\beta \Delta T l^3}{v\alpha } \\\\R_{aL}=\frac{9.8 \;\times \;\frac{1}{318} \;\times \;(75-15) \;\times \;0.15^3 }{1.750 \times 10^{-5}\; \times \;2.416 \times 10^{-5} } \\\\R_{aL}=\frac{9.8\; \times 0.00315 \;\times \;60\; \times\; 0.003375 }{4.228 \times 10^{-10} }\\\\R_{aL}=1.48 \times 10^{7}$

Also take note, g(Pr) is given by this equation:

$g(P_r)=\frac{0.75P_r}{[0.609 \;+\;1.221\sqrt{P_r}\; +\;1.238P_r]^\frac{1}{4} } \\\\g(P_r)=\frac{0.75(0.7241)}{[0.609 \;+\;1.221\sqrt{0.7241}\; +\;1.238(0.7241)]^\frac{1}{4} }\\\\g(P_r)=\frac{0.543075}{[0.609 \;+\;1.221\sqrt{0.7241}\; +\;1.238(0.7241)]^\frac{1}{4} }\\\\g(P_r)=\frac{0.543075}{[2.5444]^\frac{1}{4} }\\\\g(P_r)=\frac{0.543075}{1.2630 }$

g(Pr) = 0.430

For GrL, we have:

$G_{rL}=\frac{R_{aL}}{P_r} \\\\G_{rL}=\frac{1.48 \times 10^7}{0.7241} \\\\G_{rL}=1.99 \times 10^7$

Since the Rayleigh number is less than 10⁹, the flow is laminar and the condition is given by:

$N_{uL}=\frac{h_{L}L}{k} = \frac{4}{3} (\frac{G_{rL}}{4} )^\frac{1}{4} g(P_r)\\\\h_{L}=\frac{0.02699}{0.15} \times [\frac{4}{3} \times (\frac{1.99 \times 10^7}{4} )^\frac{1}{4} ]\times 0.430\\\\h_{L}= 0.1799 \times 62.9705 \times 0.430\\\\h_{L}=4.87\;W/m^2k$

Based on empirical correlation method, the average heat transfer coefficient for the plate is given by this equation:

$N_{uL}=\frac{h_{L}L}{k} =0.68 + \frac{0.670 R_{aL}^\frac{1}{4}}{[1+(\frac{0.492}{P_r})^\frac{9}{16}]^\frac{4}{19} } \\\\h_{L}=\frac{0.02699}{0.15} \times ( 0.68 + \frac{0.670 (1.48 \times 10^7)^\frac{1}{4}}{[1+(\frac{0.492}{0.7241})^\frac{9}{16}]^\frac{4}{19} })\\\\h_{L}=4.87\;W/m^2k$

Read more on heat transfer here: brainly.com/question/10119413

3 0

2 years ago