Randomized 4

#$&*

course phy 121

9/10 round 3:40

An automobile traveling a straight line is at point A at clock time t = 4 sec, where it is traveling at 10 m/s, to point B at clock time t = 11 sec, where it is traveling at 20.5 m/s. Point A is 75 meters from the starting point and point B is 115 meters from the starting point. What are the average velocity and the average acceleration of the automobile during the specified time? What evidence is there that the acceleration is or is not uniform? Ave vel = change in position / change in time

Ave vel = (115 m – 75m) / (11sec – 4sec)

Ave vel = 40 m / 7sec = 5.71m/sec

Ave acc = `dv / `dt.

Ave acc = (20.5 m/s – 10 m/s) / (11sec – 4sec)

Ave acc = 10.5 m/s / 7 s = 1.5 m/s

check the units; m/s / s is not m/s. You got this in the qa; refer to those calculations and be sure you understand.

It is uniform because it is with respect to clock time.

If acceleration is uniform then the average velocity on an interval, which you calculated correctly, is equal to the average of the initial and final velocities on that interval.

What do you conclude?

Good, but check those unit calculations, and please submit a revision with an answer to the question in my last note.

&#Please see my notes and submit a copy of this document with revisions and/or questions, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).

Be sure to include the entire document, including my notes.

&#

#$&*

*&$*&$