Will a Ball Take Longer To Rise or Fall?

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The discussion revolves around the motion of a ball thrown straight up, specifically examining the time it takes for the ball to rise to its maximum height compared to the time it takes to fall back to its original position, considering the effects of air friction and gravitational force.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants explore the forces acting on the ball during its ascent and descent, questioning the impact of air friction and gravitational force on the time taken for each phase of motion. Some participants suggest that the resistive forces differ between ascent and descent, while others question the role of gravitational force during the fall.

Discussion Status

The discussion is ongoing, with various interpretations being explored regarding the forces at play. Some participants express differing opinions on whether the time taken to rise and fall is the same, while others provide reasoning based on the forces involved.

Contextual Notes

Participants are considering the effects of air friction and gravitational force, with some uncertainty about how these forces interact during the ball's motion. There is an emphasis on understanding the net forces acting on the ball in both directions.

UrbanXrisis
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if I threw a ball straight up (including air friction), would it take longer for the ball to drop back to its original position from its max height or longer for the ball to rise up to its max height?

here's what I'm thinking, on the way up, there is air friction and mg going agaist the initial velocity, on the way down, it would just be air friction against the ball. Since on the way down, there is only one resistive force, then it would fall faster right?

also, air friction in this problem decreases the acceleration right?
 
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here's what I'm thinking, on the way up, there is air friction and mg going agaist the initial velocity, on the way down, it would just be air friction against the ball. Since on the way down, there is only one resistive force, then it would fall faster right?

So mg doesn't act on the way down? Are you sure?
 
the resistive force on the way up would be F=Fg+Ff

on the way down it would be F=Ff

since there is less resistive force on the way down, the ball would drop faster
 
Net force on the way up, with up as positive:

[tex]-(F_g + F_a)[/tex]

Down:

[tex]-F_g + F_a[/tex]

Finding:

[tex]-F_g - F_a (?) -F_g + F_a[/tex]

Cancel -F_g

[tex]-F_a (?) F_a[/tex]

F_a is acting AGAINST the direction of motion in both directions. It's still my opinion that it takes the same time to go up and down.
 

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