Is there lag as force is converted into acceleration?

AI Thread Summary
The discussion centers on the mechanics of a baseball being hit by a bat, specifically the timing of acceleration and contact. When the bat strikes the ball, the ball initially has zero velocity and begins to accelerate during the brief contact period. Once the bat and ball separate, the ball does not continue to accelerate; it is in free fall, affected by gravity and wind resistance. Some microscopic effects, such as electron repulsion, may occur for a fraction of a second after contact, but these do not contribute to further acceleration. Ultimately, once contact ends, the force from the bat ceases, and the ball's acceleration stops.
Poopsilon
Messages
288
Reaction score
1
Sorry for the confusing title, I'm new to physics and have been studying some classical mechanics and I have some conceptual confusion.

Say someone hits a baseball with a bat. The instant the ball and the bat make contact the ball has zero velocity, and then begins to accelerate as the swing of the bat knocks it forward. Does the entirety of this acceleration occur for the fraction of a second that the ball and bat are in physical contact? So that top speed is reached as soon as the ball and bat are no longer in contact, and from there the ball begins to decelerate due to wind resistance.

Or does the ball continue to accelerate for some amount of time even after it's no longer in contact with the bat?

Thanks.
 
Physics news on Phys.org
end contact ends force of bat. Microscopically though you could imagine that the ball is repelling away the bat just a fraction of a fraction of a second pushed by electrons e-field of both ball and bat until the e-field repelling is effectively zero.

also when you hit a ball the ball deforms and the bat bends a bit and as they separate they go back to their shape. this means that even though the bat has stopped the ball may still be in contact for a fraction of a second and then its free. the instant the bat stops its not accelerating the ball. There could even be some drag if the ball kinda stuck to the bat. Nobody goes to this depth in solving this as these effects all cancel out.

but we use the ideal case, bat hits ball and accelerates it for a certain distance and then stops. ball is now in free fall going forward but being pulled down by gravity and slowed by wind resistance.
 
Yes, as soon as the ball is no longer in contact with the bat and the force is removed there is no more acceleration.
 
jedishrfu said:
end contact ends force of bat. Microscopically though you could imagine that the ball is repelling away the bat just a fraction of a fraction of a second pushed by electrons e-field of both ball and bat.

I believe this is pretty much the definition of "contact". The atoms in the ball never "merge" with the bat, but are repelled away from them. Once the ball has reached a far enough distance they no longer feel any significant force and we can say that the two objects are no longer in contact.
 
Excellent that's what I was hoping was correct, thanks everyone =].
 
I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
Back
Top