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In nuclear fission and fusion reactions mass is converted into energy. The average person in US uses around 100,000,000 J of energy per year.

(a) Calculate the yearly energy consumption for a US population of 300 million.
(b) Using Einstein's famous formula, E = m c^2, calculate the energy that would be released if a 60 kg person were converted entirely into energy.
(c) How many years would this amount of energy support a population of 300 million?

2 Answers

4 votes

Answer:

Step-by-step 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

User Nourza
by
8.5k points
2 votes

Answer:

a) The yearly energy consumption for a US population of 300 million is
3* 10^(16) J/year

b) The energy that would be released if a 60 kg person were converted entirely into energy is
5.4* 10^(18) Joules.

c) 180 years would this amount of energy support a population of 300 million.

Step-by-step 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 =
3* 10^8

The yearly energy consumption for a US population :


100,000,000 J/year* 3* 10^8=3* 10^(16) J/year

The yearly energy consumption for a US population of 300 million is
3* 10^(16) J/year

b)
E = m* c^2

E = Energy from converted mass of m

c = speed of light

Given mass of person = m = 60 kg


E=60 kg* (3* 10^8 m/s)^2 = 5.4* 10^(18) J

c) Energy calculated in part (b) =
E=5.4* 10^(18) J

The yearly energy consumption for a US population of 300 million in an year =
3* 10^(16) J/year

Let the that would be supported by
5.4* 10^(18) Joules of energy be x.


x* 3* 10^(16) J/year=5.4* 10^(18) J


x=(5.4* 10^(18) J)/(3* 10^(16) J/year)=180 years

180 years would this amount of energy support a population of 300 million.

User Nasser Mansouri
by
7.6k points

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