Bat Hits Baseball - Force & Time Calculation

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    Baseball Physics
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Discussion Overview

The discussion revolves around calculating the time a bat is in contact with a baseball after it is pitched and hits the bat, considering the force exerted by the bat and the change in momentum of the baseball. The conversation includes aspects of physics related to force, momentum, and impulse.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant presents a calculation using the formula involving force and change in velocity, arriving at a time of 1.5 seconds, but expresses uncertainty about the correctness of this result.
  • Another participant questions the mass of the baseball, suggesting that 1.5 kg is likely a typo, as a standard major league baseball weighs 0.15 kg.
  • A later reply confirms that the initial calculation is correct given the faulty mass data, reiterating the calculation of time based on the change in momentum and force.
  • One participant humorously remarks on the implications of using an incorrectly heavy baseball in a game scenario.
  • Another participant emphasizes that the question should be approached in terms of impulse, suggesting a playful tone in the discussion.

Areas of Agreement / Disagreement

There is disagreement regarding the mass of the baseball, with some participants asserting that the 1.5 kg figure is incorrect. However, there is agreement on the calculation method used to determine the time of contact, despite the initial data being questioned.

Contextual Notes

The discussion highlights the dependence on accurate data for calculations, as the mass of the baseball significantly affects the outcome. The conversation also reflects the importance of understanding the concepts of force and momentum in physics.

Who May Find This Useful

This discussion may be useful for students or enthusiasts interested in physics concepts related to force, momentum, and impulse, particularly in the context of sports dynamics.

gnome222
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<< Moderator Note -- thread moved to the HH forums >> [/color]

a pitcher throws a 1.5kg baseball with speed 25m/s. it hits the bat and return in opposite direction with same speed. the force that bat exerted on ball is 50N. For how long was the bat touching(in contact) the ball? I used: delat t * F = m*delta velocity delta t 50N = 1.5(25-(-25)) and i got t=1.5 s. Is it correct? It does not seem like.
 
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gnome222 said:
a pitcher throws a 1.5kg baseball with speed 25m/s. it hits the bat and return in opposite direction with same speed. the force that bat exerted on ball is 50N. For how long was the bat touching(in contact) the ball? I used: delat t * F = m*delta velocity delta t 50N = 1.5(25-(-25)) and i got t=1.5 s. Is it correct? It does not seem like.
That's a pretty happy baseball. Are you sure of that 1.5 kg?

Chet
 
Chestermiller said:
That's a pretty happy baseball. Are you sure of that 1.5 kg?

Chet
yes
 
gnome222 said:
yes
A major league baseball has a mass of 5.25 oz (0.15 kg). That 1.5 kg is an obvious typo.

And, please, don't try to play baseball with a 1.5 kg baseball. If you got hit by a fastball, it would be "lights out."

Chet
 
o
Chestermiller said:
A major league baseball has a mass of 5.25 oz (0.15 kg). That 1.5 kg is an obvious typo.

And, please, don't try to play baseball with a 1.5 kg baseball. If you got hit by a fastball, it would be "lights out."

Chet
ok, but under the conditions described what would be time?
 
gnome222 said:
o

ok, but under the conditions described what would be time?
If you are asking whether you solved the problem correctly, given the obviously faulty data, then the answer is yes.

Chet
 
force is the rate of change of momentum.
Thus, you have been given the change in momentum, the force excerted.
So,
t=Change in momentum/force
=2*1.5*25/50=75/50=1.5

Yup, your answer is correct
 
This is the sort of question you have to answer on impulse. Boom boom.
 

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