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4 years ago

Please Answer this Task

1 answer:

4 0

A. Using less cars
B. Saving/Planting Trees
C. Don't build too many factories.
D. Save gas
E. You can start farming(if you can)

Those are all I know

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Use the drop-down menus to complete the statements. Outlook allows users to insert symbols and characters not located on the , b

Vera_Pavlovna [14]

Answer:

Keyboard and Mobile devices

Explanation:

got it right on edge 2021

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3 years ago

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How are engineers creating clothing that can charge your cell phone. Explain the science behind their innovation.

soldier1979 [14.2K]

Answer:

By the use of carbon nanotubes as the clothing material.

Explanation:

Carbon nanotubes is a technology designed by engineers that could make charging of the cell of a phone possible. It has some some required properties like it is strong, conductive and heat-resistant which are suitable for the purpose.

This technology which involves a progressive dipping of a pure cotton material into nafion polymer, then in a chemical solution of carbon nanotubes and finally in polystyrene until it becomes saturated and have a conductive property. The conductive cotton can be used to make such cloths which becomes conductive and produces some electromagnetic waves when there is a contact with sweat or fluid from the body. The waves generated can be used to charge a cell phone through radiation interaction.

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4 years ago

3. When you graph the motion of an object, you put ____ on the horizontal axis and ____ on the axis. a. speed, time b. dis

Papessa [141]

The answer is B. distance , Time

7 0

3 years ago

Read 2 more answers

An ocean thermal energy conversion system is being proposed for electric power generation. Such a system is based on the standar

defon

Answer:

Explanation:

Dear Student, this question is incomplete, and to attempt this question, we have attached the complete copy of the question in the image below. Please, Kindly refer to it when going through the solution to the question.

To objective is to find the:

(i) required heat exchanger area.

(ii) flow rate to be maintained in the evaporator.

Given that:

water temperature = 300 K

At a reasonable depth, the water is cold and its temperature = 280 K

The power output W = 2 MW

Efficiency $\zeta$ = 3%

where;

$\zeta = \dfrac{W_{out}}{Q_{supplied }}$

$Q_{supplied } = \dfrac{2}{0.03} \ MW$

$Q_{supplied } = 66.66 \ MW$

However, from the evaporator, the heat transfer Q can be determined by using the formula:

Q = UA(L MTD)

where;

$LMTD = \dfrac{\Delta T_1 - \Delta T_2}{In (\dfrac{\Delta T_1}{\Delta T_2} )}$

Also;

$\Delta T_1 = T_{h_{in}}- T_{c_{out}} \\ \\ \Delta T_1 = 300 -290 \\ \\ \Delta T_1 = 10 \ K$

$\Delta T_2 = T_{h_{in}}- T_{c_{out}} \\ \\ \Delta T_2 = 292 -290 \\ \\ \Delta T_2 = 2\ K$

$LMTD = \dfrac{10 -2}{In (\dfrac{10}{2} )}$

$LMTD = \dfrac{8}{In (5)}$

LMTD = 4.97

Thus, the required heat exchanger area A is calculated by using the formula:

$Q_H = UA (LMTD)$

where;

U = overall heat coefficient given as 1200 W/m².K

$66.667 \times 10^6 = 1200 \times A \times 4.97 \\ \\ A= \dfrac{66.667 \times 10^6}{1200 \times 4.97} \\ \\ \mathbf{A = 11178.236 \ m^2}$

The mass flow rate:

$Q_{H} = mC_p(T_{in} -T_{out} ) \\ \\ 66.667 \times 10^6= m \times 4.18 (300 -292) \\ \\ m = \dfrac{ 66.667 \times 10^6}{4.18 \times 8} \\ \\ \mathbf{m = 1993630.383 \ kg/s}$

3 0

3 years ago

Which of the below statements are true?

andrezito [222]

Answer:

Explanation:

Displacement is the distance from the start point to the endpoint, displacement disregard the path taken or the amount traveled.

if you start at point A, then go to point B, and back to point A, the displacement is zero because you started and ended at the same point.

for this question, pretend you started at point A, went east 20 km to point B, and then west 8 km to point C, your displacement is 12 km. 12 km is the distance between point A and point C.

4 0

3 years ago