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Homework Help: Force of gravity Homework help

  1. Oct 16, 2007 #1
    homework help!!

    1. The problem statement, all variables and given/known data

    1. The force of gravity acting on an object near Earth’s surface is proportional to the mass of the object. Why does a heavy object not fall faster than a light object?

    2. What happens to the gravitational force between two masses when the distance between the masses is doubled?

    3. According to Newton’s version of Kepler’s third law, how does the ratio (T^2/r^3) change if the mass of the sun is doubled?
  2. jcsd
  3. Oct 16, 2007 #2
    1. If you are considering the specific type of falling motion known as free-fall. Free-fall is the motion of objects under the sole influence of gravity; free-falling objects do not encounter air resistance. Massive objects will only fall faster than less massive objects if there is an appreciable amount of air resistance present.

    The explanation of why all objects accelerate at the same rate involves the concepts of force and mass. Acceleration of an object is directly proportional to the force acting on it and inversely proportional to its mass. Increasing force tends to increase acceleration while increasing mass tends to decrease acceleration. Thus, the greater force on massive objects is offset by the inverse influence of greater mass. So all objects, regardless of their mass, free-fall at the same rate of acceleration.
  4. Oct 16, 2007 #3
    1. Consider this free-fall diagram:

  5. Oct 16, 2007 #4
    Newton's Law.

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