A particle starts its motion from rest under the action of a constant force. If the distance covered in first 10 seconds is S₁ and that covered in the first 20 seconds is S₂, then

The distance travelled by a particle starting from rest and moving with an acceleration $${4 \over 3}$$m s^$$-$$2, in the third second is

A particle moves in a straight line with a constant acceleration. It changes its velocity from 10 ms^$$-$$1 to 20 ms^$$-$$1 while passing through a distance 135 m in t second. The value of t is

The positions x of a particle with respect to time t along x-axis is given by x = 9t² $$-$$ t³ where x is in metres and t in seconds. What will be the position of this particle when it achieves maximum speed along the + x direction ?