A comet with a mass of 7.95 1011 kg strikes Earth at a speed of 22 km/s.
(a) Find the kinetic energy of the comet in joules.
(b) Compare the work that is done by Earth in stopping the comet to the 4.2 1015 J of energy that was released by the largest nuclear weapon ever built. Do this by calculating how many of these bombs would be equivalent to the energy of the comet. Such a comet collision has been suggested as having caused the extinction of the dinosaurs.
I will be happy to critique your thinking. I am not much inclined to fill in your blanks.