The displacement $$x$$ (in $$\mathrm{m}$$) of a particle of mass $$m$$ (in $$\mathrm{kg}$$) moving in one dimension under the action of a force, is related to time $$t$$ (in sec) by $$t=\sqrt{x}+3$$. The displacement of the particle when its velocity is zero, will be

For a body moving along a straight line, the following $$v$$-$$t$$ graph is obtained.

According to the graph, the displacement during

A particle starts from rest. Its acceleration $$a$$ versus time $$t$$ is shown in the figure. The maximum speed of the particle will be

At a metro station, a girl walks up a stationary escalator in $$20 \mathrm{~s}$$. If she remains stationary on the escalator, then the escalator take her up in $$30 \mathrm{~s}$$. The time taken by her to walk up on the moving escalator will be