You just landed on the planet Olympus IV, famous for its sports competitions. It's a light planet: the average density is one quarter of the Earths average density. It's also a large planet: the diameter is the double of the Earths diameter. The Olympians are giving a high jump competition, and one crew member takes part. You know that on Earth he jumps 1.98 meters. The record at Olympus IV is 3.86 meters. Should you bet your salary on him winning the competition ?

(In reply to re(2): About Nine-tenths of an answer. by Eric)

Since frictional force is directly proportional to the force perpendicular to a surface (gravity, in this case), the crewman will not be able to get the traction needed to generate good lateral motion.  Also, because the gravity on Olympus IV is much less than on Earth, the crewman's gait will be much more bouncy and loping.  (And from a practical point of view, since we "just landed", the crewman will not be adept at using the lower gravity to advantage).  For these reasons, I expect his running speed to be markedly less than it is on earth, so when he translates his lateral speed to vertical speed, the result will be less than optimal and he will fall short of the record.

Posted by Bryan on 2005-03-14 17:04:43