SAT Subject Physics Practice Question 158: Answer and Explanation
4. For an object traveling in a straight line, its velocity (v, in m/s) as a function of time (t, in s) is given by the following graph.
Which graph best illustrates the object’s distance from its starting point?
Correct Answer: E
Since the given graph of v versus t is always above the t axis, that means v is never negative. From this we can conclude that the object never changes direction (because the velocity would change from positive to negative if this were true). If the object is always traveling in the same direction, its distance from the starting point must always increase. This behavior is only illustrated by the graph in E.