#$&*
course Phy 121
9/8 around 7:00
If the velocity of the object changes from 3 cm / sec to 11 cm / sec in 9 seconds, then at what average rate is the velocity changing?Ave rate = change in distance / change in time
distance can't be negative; change in position can, so think in terms of change in position / change in clock time
8cm/sec / 9sec = 0.89 cm/sec
A ball rolling from rest down a constant incline requires 8.6 seconds to roll the 68 centimeter length of the incline.
• What is its average velocity?
Ave velocity = distance / time
vAve = 68cm / 8.6sec = 7.91 cm/sec
An object which accelerates uniformly from rest will attain a final velocity which is double its average velocity.
• What therefore is the final velocity of this ball?
you've figured out the average velocity of this ball. The preceding statement tells you how to find the final velocity. This should help.
• At what average rate is the velocity of the ball therefore changing?
??????????I am not really sure how to go about answering these questions.
what does the definition of average rate of change of A with respect to B tell you about the average rate of change of velocity with respect to clock time?
For the given situation, what do you conclude that average rate is for the ball?
An automobile accelerates uniformly down a constant incline, starting from rest. It requires 15 seconds to cover a distance of 172 meters. At what average rate is the velocity of the automobile therefore changing?
Ave velocity = distance / time
vAve = 172 m / 15 sec = 11.47 m/sec
???? How would I find the rate of change if I am only given this information… there is not a way to determine the change in time and distance?
It's very good to notice that you're missing something. Most students miss this and never realize they have.
See my notes and spend up to 15 minutes trying to construct a solution, and/or inserting questions. Don't get hung up on it for longer than that, and submit what you have at that point. I want to see if you can get it from my notes, but I don't want to tie you up for hours. If you can't get it in 15 minutes, I'll give you further hints.
&#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. &#