Let's take a look!
What kind of experiment is this?
Experimental procedure and explanation:
- Let us devise a method that will enable no spilling of water when carrying it in a glass.
- First, hold the glass vertically in your hand and carry it. If your movement is not careful, the water will spill.
- Next, hang the glass with a thread. Not much water will spill, even if you shake it hard. It appears as though the glass and the water are moving together.
- When viewed from the object (the glass and water), an apparent inertial acceleration acts on the object in the direction opposite to the motion. The apparent gravitational acceleration is a combination of this inertial acceleration and the true gravitational acceleration. The thread and the glass are pointing in the direction of this apparent gravitational acceleration. The water surface becomes perpendicular to this, and the water acts as if it is part of the glass.
|[Reference]||“The Wonders of Flow,” Japan Society of Mechanical Engineering, Koudansha Blue Backs, pp. 84-89|