(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The motion of a particle is expressed by a=42-12x^{2}where a is in m/s^{2}and X is in m, with the initial condition: v=0 when x=0 and t=0

Determine v when X=6

Determine X when v becomes 0 again

2. Relevant equations

I tried using a=dv/dt so i took the anti derivative of a to find the equation of v which turned out to be 42x-4x^3 + c and then pluged in 6 for x and found v=-612m/s

but then for the second part when i tried finding the roots of the equation b i have two answers +3.2 and -3.2

So i dont know if i should use +3.2 or -3.2

Can somone tell me if im doin anything wrong? :(

3. The attempt at a solution

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# Homework Help: Mechanical acceleration and veloctiy relationship

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