newtons universal law

2. AP Physics C
Mrs. Coyle

3.  1666, England (45 years after
Kepler).

5.  If the planets are orbiting the sun , what force is
keeping them in orbit?
 What force keeps the moon in its orbit?
 Could the force of gravity be universal?
Example 2

6.  Any two objects attract each other with a
gravitational force, proportional to the product
of their masses and inversely proportional to
the square of the distance between them.
 The force acts in the direction of the line
connecting the centers of the masses.

7.  Newton’s Law is universal, it acts between any
two masses regardless of how large (planets,
stars) or how small (particles, atoms, neutrons)
they are.
 The gravitational force is weaker than the
electrical force.

9. The gravitational force place the
role of the centripetal force.