I was wondering if someone could explain the relationships between the three motion graphs (Position-Time, Velocity-Time, and Acceleration-Time). I believe that the slope of the P-T is Velocity and the slope of the V-T is Acceleration. I just want to know how they all relate to each other, and how you can find different kinematic variables using each graph.
1 Answer
Yes, that's correct. The slope of any function (position, velocity, acceleration, number of bananas, etc) plotted along the time axis is the rate of change of that function. If your graph is a straight line, it's easy to find the slope, which is just rise/run, e.g.
$$ \text{velocity} = v = \frac{\Delta x}{\Delta t} = \frac{\text{(change in position)}}{\text{(change in time)}}. $$
To find position from velocity on the other hand (or velocity from acceleration), you need the area under the velocity (or acceleration) versus time graph, since
$$ \Delta x = v\Delta t. $$
When your graph is not a straight line, the slope is changing (and areas will be harder to calculate), but the same principle holds in terms of limits, with $\Delta x\rightarrow 0$, $\Delta t\rightarrow 0$. This is where calculus comes in, with slope given by the derivative and area by the integral.