cq_1_061

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phy121

Your 'cq_1_06.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** CQ_1_06.1_labelMessages **

For each situation state which of the five quantities v0, vf, `ds, `dt and a are given, and give the value of each.

• A ball accelerates uniformly from 10 cm/s to 20 cm/s while traveling 45 cm.

answer/question/discussion: ->->->->->->->->->->->-> :

v0= 10cm/s

vf= 20cm/s

‘ds= 45cm

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• A ball accelerates uniformly at 10 cm/s^2 for 3 seconds, and at the end of this interval is moving at 50 cm/s.

answer/question/discussion: ->->->->->->->->->->->-> :

a= 10cm/s^2

‘dt= 3 seconds

Vf= 50cm/s

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• A ball travels 30 cm along an incline, starting from rest, while accelerating at 20 cm/s^2.

answer/question/discussion: ->->->->->->->->->->->-> :

‘ds= 30cm

V0= 0cm/s

A= 20cm/s^2

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Then for each situation answer the following:

• Is it possible from this information to directly determine vAve?

answer/question/discussion: ->->->->->->->->->->->-> :

First question: yes it is possible to determine vAve by adding the initial and final velocities and divide by 2.

(10cm/s+20cm/s)/2= 30cm/s /2= 15cm/s

Question 2: yes it is possible, by using the formula a= ‘dv/’dt, this will find the initial velocity, then do the same for the first question.

10cm/s^2= (50cm/s-v0)/3s

10cm/s^2*3s= 50cm/s-v0

30cm/s-50cm/s= -v0

V0= 20cm/s

vAve= (50cm/s+20cm/s)/2= 70cm/s /2= 35cm/s

Question 3: yes it is possible, by using the formula vf^2 = v0^2 + 2 a `ds, to find the final velocity then finding the average.

Vf^2= 0cm/s^2+ 2*20cm/s^2*30cm

Vf^2= 1200cm/s

Vf= sqrt1200cm/s

Vf= 34.64cm/s

vAve= (34.64cm/s+0cm/s)/2= 17.32cm/s

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• Is it possible to directly determine `dv?

answer/question/discussion: ->->->->->->->->->->->-> :

For all the questions, it is possible to determine ‘dv, since we found the initial and final velocities for each question in the previous question to find vAve. Therefore:

Question 1: 20cm/s-10cm/s= 10cm/s

Question 2: 50cm/s-20cm/s= 30cm/s

Question 3: 34.64cm/s-0cm/s= 34.64cm/s

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&#Very good responses. Let me know if you have questions. &#