Your friend tells you that if you double the distance of a spacecraft from the planet, the gravitational force is one half as strong. Do you think this is correct?

No. When the distance is doubled, the gravitational force is 1/4 times as strong, therefore, the correct answer is she is not correct

Explanation:

The gravitational force is given as follows;

Where;

m₁, and m₂ are the masses sharing the gravitational field

G = The universal gravitational constant

r = The distance between the centers of the two masses

Therefore, when the new distance, R = 2 × r, we get;

Therefore, when the distance is doubled, the gravitational force is one fourth as strong, therefore, she is not correct.

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

what is the actual question though?