What is the chemical energy content of the 100,000 kg of liquid hydrogen that was stored in the space shuttle's external fuel tank? How long could this energy power human civilization at our consumption rate of 16 TW?

the time required is 0.886 seconds

Explanation:

The computation is shown below:

As we know that the content of the chemical energy that has a calorific value of hydrogen is 141790 kJ /kg

And, the total energy stores is 100,000 kg

Now

E = 141790 ×  100,000 kJ

= 14.179 TJ

The time would be

T = E ÷ P

= 14.179 ÷ 16

= 0.886 sec

hence the time required is 0.886 seconds

hello there!

your answer is a “generator”

a generator does not create energy but instead it transforms it.

it’s basically a motor working in reverse.

there are no contact forces mentioned on the list of choices that you've provided.