Question

Can somebody help me with a simple Physics problem?

The distance vs. time graph of a car moving at constant speed should be a straight line. Why do the data points in the graph plotted from observing the motion not fall right on the line?

A) The distance is not exactly proportional to time even if the speed is exactly constant
B) The distance and time are proportional only if the correct units of meters an seconds are used
C) Data points can never look like they fall right on a straight line
D) The measurements are inexact

I will attach the image below :)

Answer 1

The best possible answer is D The measurements are inexact.

- It's not A because the time and distance are directly proportional. That is, for every change in x, there is the same relative change in y.

- B is not correct since we have already determined that the dependent and independent variables are directly proportional.

- C is obviously incorrect; trend lines do not have to pass through every point. The points that are not on the trend line in your graph most likely have incorrect values for distance, especially the distance at 6.0 s.
I hope this helps :)

Answer 2

ty so much @dirtydiana :]