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Bad White [126]

3 years ago

9

The fastest airplane in the world can travel 7200 km/hr. How long will it take the plane to go from Los Angeles to London, 8750

km away?

1 answer:

12345 [234]3 years ago

7 0

It will take about 1 hour and 12 minutes.

hope this helps!

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What type of clothing is most suitable to facilitate this? A. a pair of pants with a cord B. a flame-resistant pair of pants C.

Tasya [4]

Answer:

A

Explanation:

8 0

3 years ago

Thermopane window is constructed, using two layers of glass 4.0 mm thick, separated by an air space of 5.0 mm.

Bond [772]

To solve this problem it is necessary to apply the concepts related to rate of thermal conduction

$\frac{Q}{t} = \frac{kA\Delta T}{d}$

The letter Q represents the amount of heat transferred in a time t, k is the thermal conductivity constant for the material, A is the cross sectional area of the material transferring heat, $\Delta T$ , T is the difference in temperature between one side of the material and the other, and d is the thickness of the material.

The change made between glass and air would be determined by:

$(\frac{Q}{t})_{glass} = (\frac{Q}{t})_{air}$

$k_{glass}(\frac{A}{L})_{glass} \Delta T_{glass} = k_{air}(A/L)_{air} \Delta T_{air}$

$\Delta T_{air} = (\frac{k_{glass}}{k_{air}})(\frac{L_{air}}{L_{glass}}) \Delta T_{glass}$

$\Delta T_{air} = (\frac{0.84}{0.0234})(\frac{5}{4}) \Delta T_{glass}$

$\Delta T_{air} = 44.9 \Delta T_{glass}$

There are two layers of Glass and one layer of Air so the total temperature would be given as,

$\Delta T = \Delta T_{glass} +\Delta T_{air} +\Delta T_{glass}$

$\Delta T = 2\Delta T_{glass} +\Delta T_{air}$

$20\°C = 46.9\Delta T_{glass}$

$\Delta T_{glass} = 0.426\°C$

Finally the rate of heat flow through this windows is given as,

$\Delta {Q}{t} = k_{glass}\frac{A}{L_{glass}}\Delta T_{glass}$

$\Delta {Q}{t} = 0.84*24*10 -3*0.426$

$\Delta {Q}{t} = 179W$

Therefore the correct answer is D. 180W.

3 0

3 years ago

Suppose a net force of 7900 N is applied to slide a 950 kg crate across the floor. Compute the resulting acceleration of the cra

LiRa [457]

Explanation:

F=ma

7900=950a

a=7900/950=8.58m/s^2

4 0

2 years ago

Which of the following is not a characteristic that geologists use to identify minerals?

VikaD [51]

Geologists do not use a minerals color or streak to identify them because some minerals can have the same streak and color but the correct answer is
b) color

5 0

3 years ago

NEED HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

jasenka [17]

Answer:

She pulled the scarf from her neck and wiped her face.

4 0

3 years ago