course Phy121
September 18,2009 around 8:45 amvvvv
Thank you for the notes. They helped explain the problems." "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?
vAve= 12cm/8sec=1.5cm/sec
####So to find the average velocity I would:
(16 cm/sec – 4cm/sec) / 8sec =12cm/sec / 8sec = 1.5cm
(cm/s) / s = cm/s * 1/s = cm * 1 / (s * s) = cm/s^2.
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?
97cm/8.2sec = 11.8cm/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?
23.6cm/sec
• What average rate is the velocity of the ball therefore changing?
I am not sure what information that you are wanting here to find the solution.
#### The average rate of velocity would be 23.6 cm/sec /(8.2 sec) = 2.8 cm/sec^2
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?
132m/10sec = 13.2m/sec.
This is the average velocity.
You need to find this, but you will require more steps to get the average acceleration.