Two students are working on the same constant-acceleration problem involving a car undergoing constant acceleration, having started from rest and after a certain time having traveled a distance of 108 m. The students are to find the average velocity. Both students are required to show their work and round any intermediate answers as well as the final answer properly to 3 significant figures. Each rounded answer is to be used in the next step of calculation as they proceed. For the final answer, Student A uses the formula vavg = (xf xi)/(tf ti) getting the result 7.26 m/s, and Student B uses the formula vavg = (v0 + v)/2 getting the result 7.29 m/s. Assuming neither student makes a mistake, which student has the better answer?
a. Student A
b. Student B
c. Under significant figure rounding, both answers are equally as good.
d. The described result cannot happen; this is physics after all.
Question 2
In the case of constant acceleration, the average velocity equals the instantaneous velocity:
a. at the beginning of the time interval.
b. at the end of the time interval.
c. half-way through the time interval.
d. three-fourths of the way through the time interval.