Jumping on the Earth
WOULD A PERSON JUMPING ON THE GROUND HAVE ANY EFFECT WHAT
SO EVER ON THE MOVEMENT OF THE EARTH? MY FREIND HAS STATED THAT IT WOULD
MOVE THE EARTH BECAUSE OF NEWTONS LAW ( ACTIONS HAVING EQUAL )
MY ARGUMENT IS THAT THE EARTH IS NOT A STATIONARY DEAD OBJECT, IT IS
LIVING WITH MILLIONS OF EVENTS HAPPENING ALL THE TIME I.E. VOLCANOES ETC
AND IT IS ALSO MOVING THROUGH SPACE.
ALL THIS WOULD MEAN AN ACTION BY ONE TINY OBJECT SUCH AS A PERSON JUMPING
OULD HAVE ALMOST 0 EFFECT PERHAPS
It sounds to me like you are both right. Newton's law certainly holds despite
the large differences in mass. The fact that the earth has millions of such
events occurring all the time is irrelevant, each one has an
effect. Because of
the large differences in masses, a person jumping on the earth would have a
tiny effect on the earth's motion.
Remember also that there are two forces acting when a person jumps. There is
the force from the person's legs propelling them upward and there is the force
of gravity. The center of mass of the earth/person combination will stay the
same. When the person jumps the earth will be pushed downward while the person
is pushed upward. Gravity will act to bring the two back together with the
center of mass that they had at the beginning of the jump. Essentially there
will be no lasting effect on either of them.
Click here to return to the Physics Archives
Update: June 2012