cq_1_061

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Phy 241

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 = 10 cm/s

vf = 20 cm/s

ds = 45 cm

dt = ds/vAve

dt = 45 cm /((10 cm/s + 20 cm/s)/2)

dt = 45 cm /15 cm/s

dt = 3 sec

a = dv/dt

a = (20 cm/sec -10 cm/s) / 3 sec

a = 10 cm/sec /3 sec

a = 3.33 cm

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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 = 10 cm/sec^2

dt = 3 sec

vf = 50 cm/sec

v0 = vf - adt

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

v0 = 50 cm/sec - 30 cm/sec

v0 = 20 cm/sec

ds = v0dt + .5adt^2

ds = (20 cm/sec * 3 sec) + (.5(10 cm/sec^2) * (3 sec))

ds = 60 cm + 45 cm

ds = 105 cm

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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: ->->->->->->->->->->->-> :

v0 = 0 cm/sec

ds = 30 cm

a = 20 cm/sec^2

vf = sqrt(v0^2 + 2ads)

vf = sqrt(2 * 20 cm/sec * 30 cm)

vf = sqrt(1200 cm^2/sec^2)

vf = 34.64 cm/sec

ds = 30 cm/ (34.64 cm/sec / 2)

ds = 30 cm/17.32 cm/sec

ds = 1.73 sec

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Then for each situation answer the following:

Is it possible from this information to directly determine vAve?

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

It is possible for question 3

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Is it possible to directly determine `dv?

It is possible for question 1 and 2

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

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