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hmabe0002@email.vccs.edu
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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 ch
Find change in distance: 16cm/sec-4cm/sec=12 cm/sec
Find average rate at velocity is changing: 12 cm/sec / 8 sec= 1.5 cm
(cm/s) / (cm/s) is 1; it is not equal to cm
In any case the time interval is 8 sec, not 8 cm/sec. So your calculation should be (12 cm/s) / (8 s) = 1.5 (cm/s) * (1/s) = 1.5 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?
Divide displacement by time: 97 cm / 8.2 sec = 11.8 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?
Multiply Average velocity by 2: 11.8 cm/sec * 2 = 23.7 cm/sec
What average rate is the velocity of the ball therefore changing?
Divide displacement by time: 23.7 cm/sec / 8.2 sec = 2.89 cm
23.7 cm/sec/ (8.2 sec ) is the correct calculation, but this represents change in velocity / change in clock time, not displacement / time.
Average rate of change of velocity with respect to clock time is change in velocity / change in clock time.
Also (cm/s) / s = cm/s * 1/s = cm/s^2, not cm.
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?
Find average velocity: 132 meters / 10 seconds = 13.2 m/sec
Find final velocity: 13.2 m/sec * 2 = 26.4 m/sec
Divide final velocity by time: 26.4 m/sec / 10 sec = 2.64 m
26.4 meters/sec/ (10 sec) is the correct calculation, but (meters / sec) / sec = (meters/sec) * (1/sec) = meters / sec^2, not meters.
Rate of change of velocity with respect to clock time is change in vel / change in clock time, not final vel / time.
Since init vel is 0, change in vel is just equal to final vel. But do not think of rate of change of velocity as final vel / time. That would seriously mislead you in many future problems.
course esubmit)
hmabe0002@email.vccs.edu
Your work has been received. Please scroll to the end of the document to see any inserted notes (in boldface) and a note at the end. The note at the end of the file will confirm that the file has been reviewed; be sure to read that note. If there is no note at the end, notify the instructor through the Submit Work form, and include the date of the posting to your access page.
An object travels a distance of 32 cm in 17.6 seconds from start to finish. If its acceleration is uniform and its initial velocity zero, then what are its average velocity, acceleration and final velocity?Average velocity = displacement divided time = 32 cm / 1
= 1.82 cm/sec
Acceleration = change in velocity/change in clock time
= 3.64 cm/sec / 17.6 sec = .207 cm
Final Velocity = average velocity * 2
= 1.82 cm/sec * 2
= 3.64 cm/sec"
Good work, but be sure you are thinking in terms of change in vel / change in clock time, not final vel / change in clock time. Let me know if you have questions.