Jerk and Creep - in Mechanics - contd. from https://www.freemathhelp.com/forum/thread

[topsquark]

Yes, I heard of jerk. It is da/dt if I remember correctly (and according to your formula). Unfortunately my Physics professor never spoke about it at all other than to mention it.

BTW, I have been meaning to say that it is great to have a Physicist helping out here. THANKS!

Well thank you! I'm pleased to be here, though I don't get much chance to do my Physics-ing here.

-Dan

 

[Steven G]

I don't get much chance to do my Physics-ing here.

-Dan

Dan, please, if you have the time and desire, write up a lecture on the jerk function. What do Physicists use it for, etc? I guess engineers use it in designing cars, right??
Steve

 

[Otis]

… write up a lecture …

What?

Next up, jounce (aka: snap), crackle and pop.

 

[topsquark]

Dan, please, if you have the time and desire, write up a lecture on the jerk function. What do Physicists use it for, etc? I guess engineers use it in designing cars, right??
Steve

There's not much to say, really. If the acceleration is not constant then we can simply call it something like a(t) and use Calculus from there. I usually make a little joke about "the average jerk" in my classes. I know of no actual processes that has a constant jerk, so there's isn't much to say.

As for Engineering uses I am a theoretical Physicist, which means I know a least a little about everything, but I know almost nothing about anything practical.

-Dan

 

[Deleted member 4993]

What?

Next up, jounce (aka: snap), crackle and pop.

You forgot Creep - in Mechanics of Materials. An excellent anti-dote of jerk....

 

[JeffM]

I am guessing here (my formal academic training was in history and economics).

When an object is what is casually known as "accelerated," it is frequently not subject to constant acceleration in the physicists' sense at all. For example, when a car starts to move, it had zero acceleration before and has positive acceleration afterwards. Presumably, there is a period during which acceleration is not constant, a period during which the acceleration is increasing from zero to some measurable constant. The colloquial term "jerk" may (again a guess) reflect the perceived result on the part of passengers in a vehicle that is experiencing increasing acceleraation.