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Phy 241
Your 'cq_1_18.1' 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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A child in a slowly moving car tosses a ball upward. It rises to a point below the roof of the car and falls back down, at which point the child catches it.
During this time the car neither speeds up nor slows down, and does not change direction.
What force(s) act on the ball between the instant of its release and the instant at which it is caught? You can ignore air resistance.
answer/question/discussion: ->->->->->->->->->->->-> :
Gravity
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What happens to the speed of the ball between release and catch? Describe in some detail; a graph of speed vs. clock time would also be appropriate.
answer/question/discussion: ->->->->->->->->->->->-> :
the kid is point A.
The roof is point B
The kid releases the ball from point A to B the velocity of the ball decreases.
From point B to A the velocity of the ball increases
A graph of speed vs clock time would look a parabola concave up
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Describe the path of the ball as it would be observed by someone standing along the side of the road.
answer/question/discussion: ->->->->->->->->->->->-> :
It would look like half an ellipse concave down.
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How would the path differ if the child was coasting along on a bicycle? What if the kid didn't bother to catch the ball?
(You know nothing about what happens after the ball makes contact with the ground, so there's no point in addressing anything that might happen after that point).
answer/question/discussion: ->->->->->->->->->->->-> :
I would look more like a semi-circle, rather than an ellipse, becuase the bicycle is slower. If the kid doesnt bother to catch it, it would look like
a semi-circle concave down, but at the point he doesnt catch it, there would be a tangle line the ball would follow
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What if the child drops the ball from the (inside) roof of the car to the floor? For the interval between roof and floor, how will the speed of the ball change?
What will be the acceleration of the ball? (You know nothing about what happens after the ball makes contact with the floor, so there's no point in addressing
anything that might happen after that point).
answer/question/discussion: ->->->->->->->->->->->-> :
If the child drops the ball FROM the roof of the car, the speed of the ball would increase and the acceleration of the ball would increase as well.
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What if the child holds the ball out of an open window and drops it. If the ball is dense (e.g., a steel ball) and the car isn't moving very fast,
air resistance will have little effect. Describe the motion of the ball as seen by the child. Describe the motion of the ball as seen by an observer by the side
of the road. (You know nothing about what happens after the ball makes contact with the ground, so there's no point in addressing anything that might happen after
that point).
answer/question/discussion: ->->->->->->->->->->->-> :
If the child drops the ball out the window the child would see the ball fall away from the child in a horizontal and vertical direction
The bystander would see the same thing but from a different angle. To the bystander the ball would move along the graph of a line similiar to -sqrt(-t)
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*#&!
&#This looks very good. Let me know if you have any questions. &#