The answer is B.
The planet cannot be too hot or too cold it has to be the right distance from its sun to maintain life.
Iron and nickel are the elements most similar to cobalt
The problem ask to calculate the bullet's flight time and the bullet's speed as it left the barrel. So base on the problem, the answer would be that the flight time is 0.076 seconds and the speed of the bullet is 657.9 m/s. I hope you are satisfied with my answer and feel free to ask for more if you have questions and further clarifications.
Of the gravitational pull and other things like mass. Planet earth it,s self as you said sir.
