Q076 - Physics For Engineers And Scientists - Solutions

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Amateur Radio and Astronomy website. JO10UX

Question 76 - Review - Chapter 1

Problem:

Chimneys in the United States spew each year $8x10^6$ metric-tons of fine fly-ash into the air . This dirt settles evenly over the total area of the USA $(9.4x10^6 km^2)$

Question:

How many kg does this mean on average per square meter?

Solution:

One Metric-Ton = $10^3 kg$

The total mass of this ash is $8x10^9 kg$

$sediment = \frac{total mass}{surface}$

In [1]:
# Berekeningen
TotalMass = 8e9 # in kg
Surface = 9.4e6 * 1e6 # opp in m2
Sediment = TotalMass / Surface
print('The mean sediment in kg = Total mass in kg / Surface in m2')
print(f'    So: {TotalMass:.2e} / {Surface:.2e} = {Sediment:.2e} in kg/m2 -or- {Sediment*1e3:5.2g} g/m2')
The mean sediment in kg = Total mass in kg / Surface in m2
    So: 8.00e+09 / 9.40e+12 = 8.51e-04 in kg/m2 -or-  0.85 g/m2

سُوۡرَةُ حٰمٓ السجدة / فُصّلَت
ثُمَّ اسْتَوَىٰ إِلَى السَّمَاءِ وَهِيَ دُخَانٌ فَقَالَ لَهَا وَلِلْأَرْضِ ائْتِيَا طَوْعًا أَوْ كَرْهًا قَالَتَا أَتَيْنَا طَائِعِينَ ﴿١١
فَقَضَاهُنَّ سَبْعَ سَمَاوَاتٍ فِي يَوْمَيْنِ وَأَوْحَىٰ فِي كُلِّ سَمَاءٍ أَمْرَهَا ۚ وَزَيَّنَّا السَّمَاءَ الدُّنْيَا بِمَصَابِيحَ وَحِفْظًا ۚ ذَٰلِكَ تَقْدِيرُ الْعَزِيزِ الْعَلِيمِ ﴿١٢


Surah Fussilat: Thereafter turned He to the heaven and it was as smoke, and said Unto it and Unto the earth: come ye twain, willingly or loth. They said: we come willingly. (11) Then He decreed them as seven heavens in two days, and revealed Unto each heaven the command thereof; and We bedecked the nether heaven with lamps and placed therein a guard. That is the ordinance of the Mighty, the Knower. (12)

De hemelen en aarde (waren) een samenhangende massa. Wij hebben ze toen van elkaar gescheiden… Wij hebben de hemel tot een beschermend dak gemaakt … en de dag en de nacht, de zon en de maan geschapen. (Koran 41 11:12)


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