What percentage of the original kinetic energy is convertible?

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Homework Help Overview

The problem involves two balls colliding, with a focus on calculating the percentage of the original kinetic energy that is convertible after the collision. The subject area includes concepts from mechanics, specifically relating to collisions and kinetic energy.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the calculations for initial kinetic energy and convertible kinetic energy, with some questioning the values used and the steps taken to arrive at the final percentage.

Discussion Status

Some participants have provided their calculations and results, while others have requested clarification on the steps leading to the convertible kinetic energy value. There appears to be a mix of correct and differing interpretations of the calculations involved.

Contextual Notes

Participants are working under the constraints of homework rules, focusing specifically on part D of the problem. There is an indication that some participants have resolved their queries independently.

emily081715
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Homework Statement


Ball 1 has an inertia of 0.500 kg and ball 2 has an inertia of 0.600 kg . Ball 1 is moving away from you at 5.0 m/s, and you decide to throw ball 2 at it to make it go faster. The balls collide head-on, and the coefficient of restitution for the collision is 0.95.
Part A)How fast must ball 2 be traveling in order to double the velocity of ball 1?
ANS: 9.7 m/s
Part B) What is the initial relative velocity of the two balls?
ANS: 4.7 m/s
Part C)What is their reduced inertia?
ANS: 0.27kg
Part D )What percentage of the original kinetic energy is convertible?

Homework Equations


Kconv/Ki(x100%)

The Attempt at a Solution


Kconv/Ki (x100%)
1.215/34.477 (x100%)= 3.5%
( every answer except Part D is correct, I'm looking for help with part D only)
 
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Please show how you got the result for (d), otherwise it is impossible to tell what went wrong. I get a different value for Kconv, and that is more than a single step.
 
mfb said:
Please show how you got the result for (d), otherwise it is impossible to tell what went wrong. I get a different value for Kconv, and that is more than a single step.
Ki= (0.5)(0.500)(5)^2+(0.5)(0.600)(9.7)^2
Ki=34.477

Kconv=(0.5)(0.27)(9.7-5.0)^2
=2.98251

2.98251/34.477 (x100%)= 8.6%
 
emily081715 said:
Ki= (0.5)(0.500)(5)^2+(0.5)(0.600)(9.7)^2
Ki=34.477

Kconv=(0.5)(0.27)(9.7-5.0)^2
=2.98251

2.98251/34.477 (x100%)= 8.6%
thats the correct answer, i found my error hours earlier and don't need help anymore
 

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