The Swing of a Pendulum
  A pendulum swings because of the force of gravity.
When the pendulum is released, gravity pulls on it and
makes it swing downward. Gravity makes the pendulum
increase its speed as it swings downward. When the
pendulum starts to swing upward, the force of gravity slows
the pendulum until it stops. Then the pendulum is pulled
downward again and it swings in the other direction.
  Planet  Weight (in newtons)
  Earth   100
Mercury    38
Venus    91
Mars    38
Pluto     7
  Jupiter    253
  The pull of gravity
keeps satellites
orbiting around Earth.
What are two examples that
  illustrate Earth’s gravitational pull?
Cause and Effect A rock tumbles down a hill.
 Identify the cause and effect of this event.