Question

The velocity-time graph for the vertical of an object thrown upward from the ground which just reaches the roof of a building and returns to the ground is show in figure. The height of the building is:

Answer 1

The height of the building is the displacement covered by the object in 2.5 seconds ( time required for the velocity to be zero)

which is equal to area of the first triangle in velocity - time graph

$\Rightarrow Height=\frac{1}{2}\left(20\right)\left(2.5\right)=25m$