Question

World oil reserves amount to about 10,000 EJ, and humankind uses energy at the rate of roughly 18 TW. If all our energy came from oil, and assuming there was no growth in energy consumption, estimate the time left until we would exhaust that 10,000-EJ reserve.

Answer 1

Answer:

t=17.61 years.

Explanation:

Given that

Reserve of energy = 10,000 EJ

Energy used by human = 18 TW

We know that

$1\ E= 10^{18}$

$1\ T= 10^{12}$

So

$Reserve\ of\ energy = 10,000 \times10^{18} J$

$Reserve\ of\ energy = 10^{22} J$

$Energy\ used\ by\ human = 18 \times10^{12}\ W$

Lets t time after energy will be  exhaust

So

$18 \times10^{12}\times t=10^{22}$

$t=\dfrac{10^{22}}{18 \times10^{12}}\ s$

$t=5.55\times 10^8 \ s$

We know that

1 year = 365 days

1 year = 365 x 24 hr

1 year = 365 x 24 x 3600 s

$1year =3.15\times 10^7\ s$

So

$t=\dfrac{5.55\times 10^8 }{3.15\times 10^7}$

t=17.61 years.