Obi-Wan lands his spacecraft on an unknown planet. Visibility is poor, so he isn't able to exactly determine on which planet he has landed. He finds someone on a local communications channel and asks for directions to Earth.
"You are already on Earth," is the reply, "Wait there and I'll be right over."
Obi-Wan is suspicious, though, since he thinks it sounds a little bit like Darth Maul. So, Obi-Wan drops a lead ball of mass 168 grams from the top of his ship, which is 18 m above the surface of the planet. It takes 2.3 s to reach the ground.
(a) If Obi-Wan's mass is 74.7 kg, what would his weight be on this planet?
N