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

A particle moving along x-axis has acceleration f, at time t, given by f = f₀$$\left( {1 - {t \over T}} \right),$$ where f₀ and T are constants.The particle at t = 0 has zero velocity. In the time interval between t = 0 and the instant when f = 0, the particle's velocity (v_x) is