On Tue, 25 Mar 2008 18:27:11 -0400, "Bruce R"
wrote:


"Greg Farr" wrote in message
.. .
Just saw a commercial with a guy hitting a golf ball towards Earth;
Question; How far could the ball travel, with 1/7th gravity? W hould
something like that achieve escape velocity?

Greg
http://gregsplace.50megs.com

Now I'm not a great math wizard or anything, but if you figure it logically,
gravity on earth pulls downward at 9.8 meters per second squared. So if the
moon is 1/7 earth gravity, take the 9.8 mps and divide it by 7 and you get
1.4 meters per second squared. A squarely smacked golf ball would exceed
this but you have to remember that even though weaker, the gravity would act
upon it all the way up to the point where earth's gravity would exert more
force (free return trajectory). So you could launch it into space with a
good smack, but it would eventually fall back to the moon because I doubty
even Tiger Woods could hit it with enough force to get it to the free return
point.. I'm sure that some really smart folks at NASA could tell you the
specifics of just how long that would take, but suffice to say that at some
point, it's coming back to the moon.

Bruce



Yes, makes perfect sense, thank you for figuring it out for us.

Greg
http://gregsplace.50megs.com