PHY 201
Your 'cq_1_13.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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Seed 13.1
A ball rolls off the end of an incline with a vertical velocity of 20 cm/s downward, and a horizontal velocity of 80 cm/s. The ball falls freely to the
floor 120 cm below.
For the interval between the end of the ramp and the floor, what are the ball's initial velocity, displacement and acceleration in the vertical direction?
'ds = 120 cm
v0 = 20 cm/s
a = 980 cm/s/s
What therefore are its final velocity, displacement, change in velocity and average velocity in the vertical direction?
vf^2 = v0^2 + 2 a `ds
= 20^2 + 235200
vF = 485 cm/s
'ds = 120 cm
'dv = 465 cm/s
vAve = 242.5 cm/s
this is half of `dv; however vAve is not 1/2 `dv.
What are the ball's acceleration and initial velocity in the horizontal direction, and what is the change in clock time, during this interval?
horizontal accel: 0
v0 = 80 cm/s
Vertically: 'ds = vAve 'dt
120 = 242.5'dt
'dt = .49 seconds
What therefore are its displacement, final velocity, average velocity and change in velocity in the horizontal direction during this interval?
'ds = vAve * 'dt
= 80(.49)
= 39.2 cm
vF = 80 cm/s
vAve = 80 cm/s
'dv = 0
After the instant of impact with the floor, can we expect that the ball will be uniformly accelerated?
I do not understand this question.
Why does this analysis stop at the instant of impact with the floor?
Because the ball suddenly stops all velocity and rolls along the floor
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30 min
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Good overall, but you had a couple of errors.
&#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. &#