physics
posted by Anonymous .
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?

I wonder if you have had calculus...
velocity=dx/dt=3521t^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