### Questions about 'Jerk'

Posted:

**Thu Apr 30, 2009 1:57 am UTC**First sorry for the math equations, i don't know TeX.

Okay, the basic equations of motion are driving me nuts. I know the basics of Sf=Si+Vi(t)+1/2a(t)^2 but that works for constant acceleration. where Sf is final position, Si is initial position, Vi is initial velocity, t is time, and a is acceleration.

Is what I am wondering is what is the basic equations for mechanics with a non zero jerk?

since jerk is da/dt it would have to be J (if J symbol for jerk, i know its already impulse) Jt^3 so the units would end up as meters. and from calculus im thinking it would be 1/6J(t)^3, so the acceleration would be 1/2a(t)^2.

But if I put this in all I can come up with would be Sf=Si+Vi(t)+1/2ai(t)^2+1/6J(t)^3, where ai is initial acceleration, so when I take the derivative ill end up eventually getting J=J. since 3rd derivative of s needs to be j, 2nd a, and 1st v. by definition.

So am I getting this correct, or am I missing something? What is the correct equation if anyone knows it. This is all I can come up with, without doing a differential equation or something, and I am not really sure how I would make it. I can not find this equation anywhere online, I cant google and find anything past basic physics 1 mechanics. thanks for any help

Okay, the basic equations of motion are driving me nuts. I know the basics of Sf=Si+Vi(t)+1/2a(t)^2 but that works for constant acceleration. where Sf is final position, Si is initial position, Vi is initial velocity, t is time, and a is acceleration.

Is what I am wondering is what is the basic equations for mechanics with a non zero jerk?

since jerk is da/dt it would have to be J (if J symbol for jerk, i know its already impulse) Jt^3 so the units would end up as meters. and from calculus im thinking it would be 1/6J(t)^3, so the acceleration would be 1/2a(t)^2.

But if I put this in all I can come up with would be Sf=Si+Vi(t)+1/2ai(t)^2+1/6J(t)^3, where ai is initial acceleration, so when I take the derivative ill end up eventually getting J=J. since 3rd derivative of s needs to be j, 2nd a, and 1st v. by definition.

So am I getting this correct, or am I missing something? What is the correct equation if anyone knows it. This is all I can come up with, without doing a differential equation or something, and I am not really sure how I would make it. I can not find this equation anywhere online, I cant google and find anything past basic physics 1 mechanics. thanks for any help