an object moves in the -x direction at a speed of 30 m/s. As it passes through the origin it starts to experience a constant acceleration of 1.4 m/s^2 in the +x direction. How much time elapses before it returns to the origin?

Answer 1

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Answer 2

so when is velocity zero?
Vf=Vi+at
0=-30+1.4t
t= 30/1.4 seconds