# physics

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If the position of a particle is given by x = 35t - 7t^3, where x is in meters and t is in seconds, answer the following questions.
(a) When, if ever, is the particle's velocity zero? (Enter the value of t or 'never'.)
(b) When is its acceleration a zero?

• physics -

I wonder if you have had calculus...

velocity=dx/dt=35-21t^2.
so velocity is zero when t^2=35/32 solve for t.

acceleration= dv/dt=-42t so acceleation is zero only when t=0

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