Drag acting on ball the moment it bounces

In summary, the conversation discusses the velocity and drag of a light ball thrown at a wall, with the assumption that the wall is an xy-plane. It is determined that at the moment of collision, the ball has zero velocity in the z-axis due to changing direction, but is still moving in the x and y axes. At this moment, drag can be ignored in the z-direction, but is present in the x and y axes. The actual collision is quick and drag in any direction is negligible.
  • #1
Darkmisc
204
27

Homework Statement



Suppose a very light ball is thrown at a wall.

The wall may be thought of as an xy-plane.

At the moment the ball hits the wall, does it have 0 velocity in the x, y and z directions?

Is drag on the ball (in each respective direction) small enough to be ignored at the moment the ball hits the wall?


Homework Equations



D ~ (Av^2)/4

The Attempt at a Solution



I think the ball momentarily has 0 velocity in the z-axis since the ball is changing direction along this axis.

I think the ball will be slowed in the x and y axes at the moment it hits the wall, but its velocity in these directions will not equal zero at that instant.

Therefore, drag can only be ignored in the z-direction.
 
Physics news on Phys.org
  • #2
The actual collision with the wall takes place very quickly. Drag in any direction is so small that it can be ignored.
 
  • #3
Thanks.

Theoretically, is it correct to say that there is no drag in the z-axis at the moment of collision when the ball has zero velocity in the z direction? And that drag is present in the x and y axes at the moment of collision?
 

1. What is drag force?

Drag force is the force that acts on an object as it moves through a fluid, such as air or water. It is caused by the resistance of the fluid against the object's motion and is affected by factors such as the object's shape, size, and speed.

2. How does drag force affect a bouncing ball?

As a ball bounces, it experiences both lift and drag forces. The drag force acts in the opposite direction of the ball's motion, slowing it down. This results in a decrease in the height and distance of each bounce.

3. How is drag force related to air resistance?

Drag force is often used interchangeably with air resistance, as it refers to the same force acting on an object moving through air. However, air resistance specifically refers to the drag force on objects in air, while drag force can also apply to objects moving through other fluids.

4. Does the drag force acting on a ball change as it bounces?

Yes, the drag force acting on a ball changes as it bounces. As the ball's speed and direction change with each bounce, the drag force also changes in response. This is why a ball will eventually come to a stop due to the cumulative effects of drag force.

5. How can the drag force acting on a ball be reduced?

The drag force acting on a ball can be reduced by changing its shape, size, or surface texture. For example, a smoother surface will experience less drag than a rough surface. Additionally, increasing the ball's speed can also reduce the effect of drag force.

Similar threads

  • Introductory Physics Homework Help
2
Replies
38
Views
1K
  • Introductory Physics Homework Help
Replies
14
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
4K
  • Introductory Physics Homework Help
Replies
8
Views
3K
  • Introductory Physics Homework Help
Replies
23
Views
4K
  • Introductory Physics Homework Help
2
Replies
43
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
702
  • Introductory Physics Homework Help
Replies
3
Views
1K
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
14
Views
3K
Back
Top