Your 'cq_1_23.1' 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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Assignment 23 Seed Question 1
A wad of paper is dropped from a second-story balcony and falls through still air to the ground.
• As it speeds up, what happens to the air resistance it encounters?
answer/question/discussion: Since I could not find a good discussion of this in the book, I looked on ask.com and found through this site: http://www.glenbrook.k12.il.us/gbssci/phys/Class/newtlaws/u2l3e.html
that as speed increases, air resistance increases. Thus, as the ball is dropped from free fall from a second story height, we know that it will pick up speed as it gets closer and closer to the ground. Likewise, air resistance will also increase.
• What happens to the net force acting on it?
answer/question/discussion: The net force acting on it should be the same, as the speed increases for the was of paper, the same force against it that is exerted from air resistance will pick up, so the net effect should be the same.
• What happens to its acceleration?
answer/question/discussion: We know that F = ma, so a = F / m. If we use that set equation, we can see that if the Fnet is the same overall as we just stated and
if the mass remains constant, the acceleration should remain constant as well.
• If it dropped from a much higher point, what would happen to the net force and the acceleration?
answer/question/discussion: If dropped from a higher point, the net force and acceleration should be the same, since ‘ds does not come into play in these equations.
Air resistance increases as speed increases. This is something we commonly experience as children when we stick our hands out the windows of moving cars.
The falling object is subjected to the gravitational force (its weight) and air resistance. The net force is the sum of these two.
Air resistance acts in the upward direction, in opposition to the downward gravitational force.
The net force is therefore downward, but its magnitude is less than the gravitational force.
As the object speeds up air resistance increases, resulting in a net force of decreasing magnitude.
If the object falls long enough, the magnitude of the air resistance will approach that of the gravitational force, so that the net force approaches zero.
The magnitude of the acceleration is initially equal to g, but immediately begins to decrease.
If the object falls long enough, acceleration will approach a limiting value of zero.
Other factors being equal, the denser the object the higher the velocity at which air resistance becomes equal to weight.
A freely falling wad of loose tissue paper will quickly approach a velocity at which this occurs.
A freely falling rock would require much longer to approach a velocity at which this occurs.
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It took me about 10 minutes.
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See my notes and let me know if you have questions.
Your 'cq_1_23.1' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** **
Assignment 23 Seed Question 1
A wad of paper is dropped from a second-story balcony and falls through still air to the ground.
• As it speeds up, what happens to the air resistance it encounters?
answer/question/discussion: Since I could not find a good discussion of this in the book, I looked on ask.com and found through this site: http://www.glenbrook.k12.il.us/gbssci/phys/Class/newtlaws/u2l3e.html
that as speed increases, air resistance increases. Thus, as the ball is dropped from free fall from a second story height, we know that it will pick up speed as it gets closer and closer to the ground. Likewise, air resistance will also increase.
• What happens to the net force acting on it?
answer/question/discussion: The net force acting on it should be the same, as the speed increases for the was of paper, the same force against it that is exerted from air resistance will pick up, so the net effect should be the same.
• What happens to its acceleration?
answer/question/discussion: We know that F = ma, so a = F / m. If we use that set equation, we can see that if the Fnet is the same overall as we just stated and if the mass remains constant, the acceleration should remain constant as well.
• If it dropped from a much higher point, what would happen to the net force and the acceleration?
answer/question/discussion: If dropped from a higher point, the net force and acceleration should be the same, since ‘ds does not come into play in these equations.
Air resistance increases as speed increases. This is something we commonly experience as children when we stick our hands out the windows of moving cars.
The falling object is subjected to the gravitational force (its weight) and air resistance. The net force is the sum of these two.
Air resistance acts in the upward direction, in opposition to the downward gravitational force.
The net force is therefore downward, but its magnitude is less than the gravitational force.
As the object speeds up air resistance increases, resulting in a net force of decreasing magnitude.
If the object falls long enough, the magnitude of the air resistance will approach that of the gravitational force, so that the net force approaches zero.
The magnitude of the acceleration is initially equal to g, but immediately begins to decrease.
If the object falls long enough, acceleration will approach a limiting value of zero.
Other factors being equal, the denser the object the higher the velocity at which air resistance becomes equal to weight.
A freely falling wad of loose tissue paper will quickly approach a velocity at which this occurs.
A freely falling rock would require much longer to approach a velocity at which this occurs.
** **
It took me about 10 minutes.
** **
See my notes and let me know if you have questions.