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Olegator [25]
3 years ago
14

Suppose a person (height of 1.8 m) walks in a room installed with a pyroelectric infrared (PIR) motion detector. The distance be

tween the person and the PIR detector is 5 m. The PIR detector sensor is 3 cm x 1 cm in size.
Estimate the radiated power at the surface of the sensor from the person. Assume that emissivity of human skin/fabric and sensor cap is 0.9. Assume that the person’s body temperature is 37°C and the temperature at the surface of PIR detector is at 18°C. Also assume that there is no radiated power loss through air and Fresnel lens. You can roughly estimate surface area of the person.
Engineering
1 answer:
3241004551 [841]3 years ago
8 0

Answer: b is your best option

Explanation:

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Input Energy ---> Output Energy
uranmaximum [27]

Answer:

motion ------> electrical. winds push the turbines which generate a magnetic fields which in turn, generates electricity

4 0
2 years ago
Calculate the wire pressure for a round copper bar with an original cross-sectional area of 12.56 mm2 to a 30% reduction of area
dybincka [34]

Answer:153.76 MPa

Explanation:

Initial Area\left ( A_0\right )=12.56 mm^2

Final Area\left ( A_f\right )=0.7\times 12.56 mm^2=8.792 mm^2

Die angle=30^{\circ}

\alpha =\frac{30}{2}=15^{\circ}

\mu =0.08

Yield stress\left ( \sigma _y \right )=350 MPa

B=\mu cot\left ( \aplha\right )=0.2985

\sigma _{pressure}=\sigma _y\left [\frac{1+B}{B}\right ]\left [ 1-\frac{A_f}{A_0}\right ]^B

\sigma _{pressure}=350\left [\frac{1+0.2985}{0.2985}\right ]\left [ 1-\frac{8.792}{12.56}\right ]^{0.2985}

\sigma _{pressure}=153.76 MPa

8 0
3 years ago
List and describe three classifications of burns to the body.
DiKsa [7]

AnswerWhat Are the Classifications of Burns? Burns are classified as first-, second-, or third-degree, depending on how deep and severe they penetrate the skin's surface. First-degree burns affect only the epidermis, or outer layer of skin. The burn site is red, painful, dry, and with no blisters.

Explanation:

8 0
3 years ago
Read 2 more answers
Two particles have a mass of 7.8 kg and 11.4 kg , respectively. A. If they are 800 mm apart, determine the force of gravity acti
aleksley [76]

Answer:

A) About 9.273 \times 10^{-9} newtons

B) 76.518 newtons

C) 111.834 newtons

Explanation:

A) F_g=\dfrac{GM_1M_2}{r^2} , where G is the universal gravitational constant, M 1 and 2 are the masses of both objects in kilograms, and r is the radius in meters. Plugging in the given numbers, you get:

F_g=\dfrac{(6.67408 \times 10^{-11})(7.8)(11.4)}{(0.8)^2}\approx 9.273 \times 10^{-9}

B) You can find the weight of each object on Earth because you know the approximate acceleration due to gravity is 9.81m/s^2. Multiplying this by the mass of each object, you get a weight for the first particle of 76.518 newtons.

C) You can do a similar thing to the previous particle and find that its weight is 11.4*9.81=111.834 newtons.

Hope this helps!

3 0
3 years ago
help me please help me please help me please help me please help me please help me please help me please help me please help me
kakasveta [241]

Answer:

With what?

Explanation:

Brainliest?

7 0
3 years ago
Read 2 more answers
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