posted by danielle on .
a marble is dropped from the top of a skyscraper. Is the work done by earths gravitational force on the marble equal to, smaller than or larger them that done by the marbles gravitational force on earth? Why?
newtons 3rd law: force on marble due to earths grav. field is equal to force on earth due to marbles grav. field
Work= force * distance
marble drops significant amount but earth doesnt move by any significant amount
work done by earth is much larger
in freefall as the earth and the marble both are, when the marble is falling, the earth Does move toward the marble. It moves in proportion to the differences in the 2 masses. the work done is equal. Imagine if the marble was .50 the mass of the earth, or the same, or 2 times.