Question
Fri March 20, 2015 By: Deebu Raghv

So when the body moves up, acceleration= -g and the graph looks like what was drawn before for a decelerating body. Then when the body is moving downwards, acceleration= +g , now why does this graph have a curve similar to a decelerating body? Shouldn't the curve of this graph be in the opposite direction? How can I insert images here? It will be much easier to explain the question if I can upload images.

Expert Reply
Romal Bhansali
Fri March 20, 2015
Yes. You are right in saying that the curve should be on the other side of the x-axis.
However, we are drawing the curve considering ground as the origin. So, the displacement is w.r.t ground.
Hence, for top position displacement is maximum and it drops to zero when the body reaches ground level.
 
Now, if we draw only the graph of falling body w.r.t to top as the origin, then the displacement will be negative and the curve will be on the other side of the x-axis.
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