[spacefire5458]

When a pitcher throws a ball after the ball leaves his hand is there a force still acting on it?
Thanks;)

[Capuchin]

Only gravity and air resistance.

From F=ma we see that force causes acceleration, not velocity. This is important and is something that people who are just starting to study physics find hard to grasp.

Something that is moving at constant velocity has no force acting upon it. This seems counter-intuitive from our experience of the world, but when you examine things more closely, you see that it is the case.

[ebaines]

There are also the aerodynamic effects that create lift on the ball, depending on the spin the pitcher uses. As the ball spins the seams rotate and cause lift on one side of the ball and drag on the other - this is what causes a curve ball to curve, a fastball to appear to rise (actually, a fastball doesn't actually rise - it just doesn't drop as much as it would under the action of gravity alone), and a sinker to seem to "drop off the edge of a table."

Capuchin - you can be forgiven for missing this - in cricket you don't really have to worry about aerodynamic effects as much as we Americans do in baseball.

[Capuchin]

Haha, yes, magnus effects are also in action (we still play plenty of golf!), but I believe that spacefire is really just trying to understand the misconception that the ball is still moving although no forward force acts on it.