Question

Draw a velocity versus time graph for a stone thrown vertically upwards and then coming down after attaining the maximum height.

Answer 1

This attachment explains v-t graph for a stone thrown vertically upwards and then coming down after attaining the maximum height.

Answer 2

there's a gap on point h.as the object stops for a time while coming down.
and the velocity line goes up as velocity increases while coming down.
and time spends with respect to the object.