Is it alright to put the independent variable on the Vertical axis?

well, my dependent variable is time and my independent variable is distance. i am trying to calculate the velocity. the velocity is the gradient: rise/run. if i have my d.v on the vertical axis, my gradient will be time/distance, which does not equal velocity. the thing is all my teachers cant stress enough that you have to put the d.v on the vertical axis. so the question is: is it alright to put the independent variable on the Vertical axis? please, thanks heaps