absence of friction...no air resistance
A simple pendulum will definitely not swing continuously in air. The pendulum would lose energy to its surroundings in overcoming air resistance.
Because of the air resistance which causes the pendulum to gradually lose energy.
Two conditions required for cloud formation are cooling air to reach its dew point temperature and the presence of particles, such as dust, smoke, or salt, for water vapor to condense upon and form droplets.
Three conditions required for a thunderstorm to form are: moisture in the atmosphere, unstable air that can rise rapidly, and a lifting mechanism such as a cold front or warm air rising from the ground.
* Rising Unstable air * moisture * Air cools with an increasing altitude
ground temperature below freezing, and air temperature slightly above freezing.
Broke
Probably the movement on a swing can be approximated by assuming that the magnitude of each swing will be a certain percentage of the previous swing (because of lost energy).
The simile in the poem "Boy on a Swing" compares the boy's swing to a "giant bird on the wing" to convey the image of the swing soaring through the air as if it were a bird in flight.
Friction of air normally called drag (or air resistance), it could be argued that gravity also takes effect in stopping the swing, if it was only drag the swing could stop ten feet in the air, and if it was just gravity it wouldn't stop due to the laws of mass and momentum. The drag reduces the momentum, therefore making the swing slow to a stop and gravity keeps it as close to the ground as possible.
the swing is produced by the movement of the wind and completely depends upon the movement of the wrists of the bowlers.
Two atmospheric conditions required to produce thunderstorms are instability, which allows warm air to rise rapidly, and moisture, which provides the necessary fuel for cloud formation and storm development. When these conditions are met, thunderstorms are more likely to form and produce lightning, thunder, and heavy rainfall.