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2 years ago

6

The intensity of electromagnetic waves from the sun is 1.4kW/m2 just above the earth's atmosphere. Eighty percent of this reache

s the surface at noon on a clear summer day. Suppose you think of your back as a 30.0 cm × 51.0 cm rectangle. How many joules of solar energy fall on your back as you work on your tan for 1.30 hr ?

2 answers:

zalisa [80]2 years ago

6 0

Explanation:

Below is an attachment containing the solution.

Arlecino [84]2 years ago

3 0

Answer:

$E=8.02*10^{5}J$

Explanation:

Given data

Electromagnetic waves from the sun is I=1.4kW/m² at 80%

Area a=(0.30×0.51)m²

Time t=1.30 hr

To find

Energy E

Solution

The energy received by your back is calculated as:

$E=Pt=Iat\\E=(0.80)(1400W/m^{2} )(0.30*0.51m^{2} )(1.30*3600s)\\E=8.02*10^{5}J$

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Answer:

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2 years ago

series RC circuit is built with a 15 kΩ resistor and a parallel-plate capacitor with 18-cm-diameter electrodes. A 18 V, 36 kHz s

andre [41]

Answer:

$d=1.84\ mm$

Explanation:

<u>Capacitance</u>

A two parallel-plate capacitor has a capacitance of

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$w=2\pi f=2\pi \cdot 36000=226194.67\ rad/s$

Solving for C

$\displaystyle C=\frac{1}{wX_c}$

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$Z^2=R^2+X_c^2$

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$X_c^2=Z^2-R^2$

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$\displaystyle X_c^2=Z^2-R^2=\left(\frac{\sqrt{2}V}{I_p}\right)^2-R^2$

Or, equivalently

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$X_c=36176.34\ \Omega$

The capacitance is now

$\displaystyle C=\frac{1}{226194.67\cdot 36176.34}=1.22\cdot 10^{-10}\ F$

The radius of the plates is

$r=18\ cm/2=9 \ cm = 0.09 \ m$

The separation between the plates is

$\displaystyle d=\frac{8.85\cdot 10^{-12} \cdot \pi\cdot 0.09^2}{1.22\cdot 10^{-10}}$

$d=0.00184\ m$

$\boxed{d=1.84\ mm}$

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2 years ago

The emt must assume that any unwitnessed water-related incident is accompanied by:________

natta225 [31]

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1 year ago

A spring is hung from the ceiling. A 0.442-kg block is then attached to the free end of the spring. When released from rest, the

siniylev [52]

Answer:

$K=58.8N/m$

Explanation:

From the question we are told that:

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3 years ago

Find the equivalent resistance of this

frosja888 [35]

Answer:

Re=160ohm

Explanation:

Step#1

Rt=R1+R2 ( because both are in series)

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Step#2

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3 years ago