Particle start moving from rest with an acc. a along positive x axis for time t. After time t it reverse its direction of acc. keeping the magnitude same. After what time from start it will return its initial position.

It will take t(2^1/2 +2) seconds to come back to its initial position

meenakshi,

          at time t,itsfinal velosity is 'at',after change in direction becomes initial.find the distance travelled.let returning time t' . substuting in 2 equation of motion get a quadratic equation in t &t' . find t' &add t .ans-t(2+2^1/2)

meenakshi,

    at time t,its final velosity is 'at',after change in direction itbecomes initialvelocity.find the distance travelled.let returning time t' . substuting in 2nd equation of motion get a quadratic equation in t &t' . find t' &add t .ans-t(2+2^1/2)