If you have stood in front of a fireplace or near a campfire, you have felt the heat transfer known as radiation. The side of your body nearest the fire warms, while your other side remains unaffected by the heat. Although you are surrounded by air, the air has nothing to do with this transfer of heat. Heat lamps, that keep food warm, work in the same way. Radiation is the transfer of heat energy through space by electromagnetic radiation.

5 0

4 years ago

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Why does -2(x + 3y) = 18 equal y=-3-x/3? Please helppp

Citrus2011 [14]

Step-by-step explanation:

You're asking why

${- 2(x + 3y) = 18} = y = - 3 - \frac{x}{3}$

let's transpose the first equation for y

-2x-6y=18

-6y=18+2x

6y=-18-2x

y=-18/6-2x/6

y=-3-⅓x as required

8 0

3 years ago

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The sum of the lengths of two opposite sides of the circumscribed quadrilateral is 10 cm, and its area is 12 cm2. Find the radiu

PtichkaEL [24]

Answer:

1.2 cm

Step-by-step explanation:

The area of sircumscribed quadrilateral over a circle is equal to

$A=s\cdot r,$

where s is semi-perimeter of the quadrilateral and r is the radius of the circle.

Use property of circumscribed quadrilateral: The sums of the opposite sides are equal.

So, if the sum of two opposite sides of the circumscribed quadrilateral is 10 cm, then the sum of another two sides is also 10 cm and the perimeter of the quadrilateral is 20 cm. Hence,

$s=\dfrac{20}{2}=10\ cm$

Now,

$A=s\cdot r\\ \\12=10r\\ \\r=\dfrac{12}{10}=1.2\ cm$

8 0

3 years ago

What is the fraction eight twentieths in its simplest form?

Nostrana [21]

Both the numerator and denominator are divisible by 4, meaning that when they are both divided by this number they wll be in their simplest form.

e.g. 8/4=2 and 20/4=5

Therefore the simplest form is 2/5

7 0

3 years ago