- #1

LT72884

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- Homework Statement
- A particle traveled in a straight line in such a way that its distance (S) from a given point on that line after time (t) was S= 20t^3 -t^4 The rate of change of acceleration at time t=2 is what value?

- Relevant Equations
- S = 20t^3 - t^4

A particle traveled in a straight line in such a way that its distance (S) from a given point on that line after time (t) was S= 20t^3 -t^4 The rate of change of acceleration at time t=2 is what value?ok, I am kind of stuck on this very simple problem. It should be as simple as taking the derivative twice, and plugging in 2 at the end..

so if S = 20t^3 - t^4 then

V = 60t^2 - 4t^3 and

acceleration = 120t-12t^2 plug in 2 for t and it should be 240-48 = 192 but apparently the answer is 72... why?

am i not finding acceleration but really finding jerk? so i needed to do 3 derivs?

thanks

so if S = 20t^3 - t^4 then

V = 60t^2 - 4t^3 and

acceleration = 120t-12t^2 plug in 2 for t and it should be 240-48 = 192 but apparently the answer is 72... why?

am i not finding acceleration but really finding jerk? so i needed to do 3 derivs?

thanks