French equivalent of Retard and Advance, indicating which direction to turn the pendulum regulating nut to sped up or slow down a clock. An old book written in English claimed R & A was just the initials of an inventor(s) who was developing an improved pendulum. I've never seen anything that would validate to disclaim either.
The popular formula for the period of a pendulum works only for small angular displacements. In deriving it, you need to assume that theta, the angular displacement from the vertical, measured in radians, is equal to sin(theta). If not, you need to make much more complicated calculations. There are also other assumptions to simplify the formula - eg string is weightless. The swing of the pendulum will precess with the rotation of the earth. This may not work if the pendulum hits its stand! See Foucault's Pendulum (see link). The motion of the pendulum will die out as a result of air resistance. Thermal expansion can change the length of the pendulum and so its period.
"ms" may be short for meters per second.It is possible that somebody was talking about velocity; in this case, "north" is the direction of the movement.
You mean that we shouldn't be able to see the light if we stand at right angle to its movement? Well, this happens with laser rays. For the non-laser light it does not happen for two reasons. First, if the source of light emits light all over the space, and you are in that space, then there is no room for you to stand in order to be at right angle to its movement. Second, even if the source of light does not emit light all over the space, and you stand at right angle to its movement, the light scatters in the air, and it comes into our eyes.
A podium. Which, increasingly, people are getting confused with a "lectern". You stand ON a podium. You stand BEHIND a lectern.
retort stand
The popular formula for the period of a pendulum works only for small angular displacements. In deriving it, you need to assume that theta, the angular displacement from the vertical, measured in radians, is equal to sin(theta). If not, you need to make much more complicated calculations. There are also other assumptions to simplify the formula - eg string is weightless. The swing of the pendulum will precess with the rotation of the earth. This may not work if the pendulum hits its stand! See Foucault's Pendulum (see link). The motion of the pendulum will die out as a result of air resistance. Thermal expansion can change the length of the pendulum and so its period.
dorsiflexion
This is a puzzling question as there was no holocaust movement. The Nazis did not stand for election on a platform of genocide.
Rapid air movement
Lesbian, Gay, Bi, Trans
8 hour work day
dorsiflexion
nonrapid eye movement
Rapid Eye Movement
Plantar Flexion
Circulation. Sensation. Movement
Rapid Eye Movement.