phy 201
Your 'cq_1_02.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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The problem:
A graph is constructed representing velocity vs. clock time for the interval between clock times t = 5 seconds and t = 13 seconds. The graph consists of a straight line from the point (5 sec, 16 cm/s) to the point (13 sec, 40 cm/s).
What is the clock time at the midpoint of this interval?
answer/question/discussion: 9secs; I found the midpoint by adding the two points and dividing by 2
What is the velocity at the midpoint of this interval?
answer/question/discussion: I used the same method as above and found it to be 28cm/sec
How far do you think the object travels during this interval?
answer/question/discussion: 24 cm; the average velocity of this line was 3cm/sec and the total time of this interval was 8 sec. I multiplied the velocity * time to find the total distance.
By how much does the clock time change during this interval?
answer/question/discussion: 8 seconds this was easy to find it was the difference between the start and finish time
By how much does velocity change during this interval?
answer/question/discussion: 24cm/sec this was also easy to find using the same method as above
What is the average rate of change of velocity with respect to clock time on this interval?
answer/question/discussion: I will use the equation change in a /change in b to get 24cm/sec / 8cm/sec = 3cm/sec
What is the rise of the graph between these points?
answer/question/discussion: -24 the rise is the difference between the two y coordinates
What is the run of the graph between these points?
answer/question/discussion: -8 this is the differenc between the two x coordinates
What is the slope of the graph between these points?
answer/question/discussion: rise/run = slope so 24/8 = 3
What does the slope of the graph tell you about the motion of the object during this interval?
answer/question/discussion: since its positive the motion is speeding up as the points indicate since the end velocity is greater than the start.
What is the average rate of change of the object's velocity with respect to clock time during this interval?
answer/question/discussion: change in a /change in b = 24 / 8 = 3
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Professor Smith,
I am confused because my chapter 1 in Giancoli does not deal any with acceleration and velocity yet we were supposed to read over this chapter and do problems. Velocity and Accel are not explained till chapter 2 and we are answering questions related to these topics in many assignments.
Velocity and acceleration have been defined for you in your qa's and elsewhere, and you're doing a good job with these ideas.
By the time you see things in your text, you will have already encountered them in experiments and in questions which are based on fundamental definitions and common sense.
The reason for this approach is that very few students are prepared to read and understand a physics textbook at this level. You're doing well and I suspect you're one of those who could, but even you will find the book much easier to understand by virtue of having experienced typical systems and thought through the ideas before you read them.
Most of your answers are good, but there are a couple of incorrect procedures.
&#At least part of your solution does not agree with the solution and comments given at the link below. You should view the solution at that link and self-critique as indicated there.
Solution
This link also expands on these topics and alerts you to many of the common errors made by students in the first part of this course. &#