What causes a curve ball to curve?

  • Thread starter Thread starter Gonzolo
  • Start date Start date
  • Tags Tags
    Ball Curve
Click For Summary

Discussion Overview

The discussion centers on the physical principles behind the curving of a curve ball in sports, specifically exploring the roles of air pressure, spin, and friction. Participants examine the Magnus effect and its implications in different atmospheric conditions, such as on Mars.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the role of friction in the curving of a ball, noting that faster objects typically experience more friction, which seems counterintuitive in the context of curve balls.
  • Another participant explains that the spin of the ball affects air movement around it, leading to differences in pressure on either side, which is described as the Magnus effect, likening it to the Bernoulli principle.
  • A participant suggests that the thinner atmosphere on Mars could alter the behavior of a curve ball, speculating that lower air density might change the dynamics at play.
  • Another participant agrees that on Mars, the lack of sufficient air pressure would lead to friction being the dominant force, implying a different outcome for the curve ball's trajectory.

Areas of Agreement / Disagreement

Participants express differing views on the role of friction in the context of curve balls, particularly when comparing Earth to Mars. While some agree on the influence of the Magnus effect, the discussion remains unresolved regarding the overall impact of friction.

Contextual Notes

The discussion highlights the dependence on atmospheric conditions and the assumptions regarding air pressure and density, which are not fully resolved in the context of the curve ball's behavior.

Gonzolo
If I try to explain it with friction, it doesn't make sense, because faster things have more friction. In curve balls though (ping-pong, trackball, baseball), the ball curves toward the slower side. So I can't seem to use friction as an explanation. What's going on?
 
Engineering news on Phys.org
The spin of the ball is allowing air to move more quickly on the side spinning with the wind, and slower on the side that is spinning against the wind. The faster-moving air generates less pressure on the side that is spinning with the wind. This is called the Magnus effect, and is very much like the Bernoulli principal.

Interesting note: in an issue of Popular Science I read an article where some graduate students, using a fluid dynamics simulation program, proved that a curveball would curve the opposite way on Mars.
 
Thanks, I knew there was a simple explanation.

So for Mars, I suppose it is because the density is less? Is my friction explanation above any good for Mars by any chance?
 
Exactly! In the thinner atmosphere on Mars, there isn't sufficient air pressure to make a differential between the pressures on opposite sides of the ball, and friction becomes the dominant force.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
5K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 36 ·
2
Replies
36
Views
9K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
14
Views
4K
  • · Replies 27 ·
Replies
27
Views
8K