How long is a pendulum stationary before it changes direction?

That would depend upon the resolution at which you can perceive the smallest movement.

Technically its not a measurable duration but rather an instataneous point where velocity decreases to zero from a given direction of travel while under the effects of an acceleration that causes a change of direction. Since acceleration is dv/dt and the object is always under its effect any measurement across a duration of time would thus reslut in a change in velocity across that time period with its associated displacement (distance traveled).

How long thus inferrs a period of time or delta T (dt). Since the pendulum is always under the constant acceleration of gravity any delta T no matter how small results in movement.

Inorder to have a small duration all you can do with delta T is make it approach zero but never actually reach zero. If t1 = t2 you have a delta of zero but you are not spanning a duration of time.

Thus a pendulum is stationary only in an instant (single point of time) and not across a duration of time.

For real world pendulum, the bearing has at least a tiny amount of friction and transient vibrations travel on the pendulum, so several direction reversals occur within a few nanoseconds of the farthest from the straight down position for various parts of the pendulum, So some portion of the pendulum is esentually stationary for about one nano second, but our instruments typically can not resolve all of these transients. Neil

The pendulum is just moving in a different plane to what you imagine a sine wave to move. If you attached the pendulum to a pen and moved a piece of paper underneath it it would form a sinusoidal wave.

(So side to side motion would become the horizontal motion)

Hope you understand what i mean :)

besides to the different posters: The previous testomony, The Septuagint [translated from Hebrew to Greek someplace 250 BC] became in placed at that ingredient, used even until now Jesus' time. the hot testomony became written 35-one hundred advert and translated to latin via St Jerome, sometimes 4 hundred advert. it continues to be on parchments and study interior the church, or preached orally. So, there is not any NEW TESTAMENTS IN A e book/BIBLE form at that ingredient compiled with Septuagint.' Bible on my own' thought isn't in life at that ingredient as there is not any e book to call bible. It became using Oral custom up until 1400 whilst the 'compiled e book form bible' ultimately hit the printing press. In different words, it took the Catholic Church approximately 4 hundred years of accumulating, enhancing, and sorting the classic manuscripts and have been given revealed in 1400. there have been additionally distinctive uninspired writings [apocryphal books] that have been floating around that weren't cannonized.

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