course Phy 201
I am having trouble seeing the difference in rate and velocity. The book uses the term speed so I may not have done the problems correctly." "If the velocity of the object changes from 4 cm / sec to 16 cm / sec in 8 seconds, then at what average rate is the velocity changing?
4cm/s - 16cm/s /8 = -12/8 = -1.5 cm/s/s
A ball rolling from rest down a constant incline requires 8.2 seconds to roll the 97 centimeter length of the incline.
* What is its average velocity?
vAVE = diplacement/time elasped = fp -ip/time elasped
97-0/8.2 s = 11.829 cm/s
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?
23.66 cm/s
* What average rate is the velocity of the ball therefore changing?
Isn't this the same as above ...it changes at a reat of 11.829 cm /s??
Average rate of change of velocity is (change in velocity) / (change in clock time). Your final result does not follow from this definition. What is the change in velocity? What is the change in clock time? What therefore is the average rate of change of velocity with respect to clock time? Please answer these questions and resubmit. Be sure to include your original work and this comment.
An automobile accelerates uniformly down a constant incline, starting from rest. It requires 10 seconds to cover a distance of 132 meters. At what average rate is the velocity of the automobile therefore changing?
distance/time = 132m/10s =13.2m/s
Average velocity is vAve = `ds / `dt, which is what you calculated here. Average rate of change of velocity is (change in velocity) / (change in clock time). You have not calculated this quantity. Please calculate the average rate of change of velocity for this situation and resubmit this second question; if necessary you may of course submit with a question of your own. Be sure to include your original work and this comment.