Galileo's
hypothesis of "all objects are affected by gravity" was proven on the
moon during an Apollo mission. (when there is no air or drag on an object, all
objects are affected equally by gravity). So, here's your FUN Physics lesson
for the day:
1) Galileo
realized that a falling body picked up speed at a constant rate - in other
words, it had constant acceleration.
2) He also
made the crucial observation that, if air resistance and buoyancy can be removed
all bodies fall with the same acceleration, bodies of different weights
dropped together reach the ground at the same time. (Thus, the Hammer and
Feather drop experiment here)
3) Galileo
also noted that if a ball rolls without
interference on a smooth horizontal surface, and friction and air
resistance are removed, it will move with constant speed in a fixed direction (OR
-its velocity
remains constant)
Galileo considered the motion of an object
when not subject to interference as its “natural” motion. SO, natural
horizontal motion is motion at constant velocity, and natural vertical motion
is falling at constant acceleration.
VIDEO: The
mythbusters repeated the famous "hammer and feather drop" in a vacuum chamber at
NASA. Note how the feather bounces almost the same amount as the hammer upon
falling.
Video: https://youtu.be/7eTw35ZD1Ig
>
Source: http://galileo.phys.virginia.edu