# Draw the position time graph of a body moving with zero velocity.

## Main Question or Discussion Point

Draw the position - time graph of a body moving with zero velocity.
I drew the graph (parallel to x-axis) and got full marks . And one of my friend drew the graph (coinciding x-axis) but , he got only 0.5 marks out of 2 . When he asked the teacher, she said that the position = 0 is not defined .But in many of the graphs we start from position = 0.So, what is the mistake in my friend's answer? Isn't his answer correct?

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In a position-time graph any path parallel to the x axis would be correct. The body could have started at 1m away and stayed there.
In a displacement-time graph (which is how it's normally stated) then it has to be along the axis because the displacement (ie distance from starting point) can't change from zero

So , my friend's answer is correct , isn't it ?

If the problem was as you stated, and did not elaborate, then it seems to me the teacher might be unreasonable. If the body happens to be at x=0 with zero velocity, then its path will be on the x axis. If the problem doesn't also ask you to specify the starting coordinates of the body, then your friend seems to have answered it correctly. It might also depend on whether or not your teacher had told the class that the starting position should be stated along with the position-time graphs, and that the necessity of doing so in exams was implied.

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