Respuesta :
Answer:
a) The yearly energy consumption for a US population of 300 million is [tex]3\times 10^{16} J/year[/tex]
b) The energy that would be released if a 60 kg person were converted entirely into energy is [tex]5.4\times 10^{18} [/tex] Joules.
c) 180 years would this amount of energy support a population of 300 million.
Explanation:
a) Average energy consumed by single person of US = 100,000,000 J/year
Then 300 million US citizen will consume:
300 million = 300 × 1,000,000 = [tex]3\times 10^8[/tex]
The yearly energy consumption for a US population :
[tex]100,000,000 J/year\times 3\times 10^8=3\times 10^{16} J/year[/tex]
The yearly energy consumption for a US population of 300 million is [tex]3\times 10^{16} J/year[/tex]
b) [tex]E = m\times c^2[/tex]
E = Energy from converted mass of m
c = speed of light
Given mass of person = m = 60 kg
[tex]E=60 kg\times (3\times 10^8 m/s)^2 = 5.4\times 10^{18} J[/tex]
c) Energy calculated in part (b) = [tex]E=5.4\times 10^{18} J[/tex]
The yearly energy consumption for a US population of 300 million in an year = [tex]3\times 10^{16} J/year[/tex]
Let the that would be supported by [tex]5.4\times 10^{18} [/tex] Joules of energy be x.
[tex]x\times 3\times 10^{16} J/year=5.4\times 10^{18} J[/tex]
[tex]x=\frac{5.4\times 10^{18} J}{3\times 10^{16} J/year}=180 years[/tex]
180 years would this amount of energy support a population of 300 million.
Answer:
Explanation:
2/7 = 8/28
1/4 = 7/28
Therefore Mr Pham mowed more.
8+7 = 15 so 15/28 of lawn has been mowed, therefore 13/28 of the lawn is left still to be mowed. NO RIGHT
