Roth+Lab+13+Video+Analysis+of+Elastic+and+Inelastic+Collisions

Lab 13 Video Analysis of Elastic and Inelastic Collisions Momentum
 * Elastic Collision 1**

(m1*v1initial) + (m2*v2initial) = (m1*v1final) + (m2*v2final) (.515)*(.6679) + (.515)*(0) = (.515)*(.03735) + (.515) * (.5649) .343 kg*m/s should equal .310 kg*m/s Momentum should be conserved, but that is not the case, perhaps incorrect masses were reported. .310/.343= .904 Only 90.4% of the momentum was conserved.

Kinetic Energy

(1/2) m1 (v1initial)^2 + (1/2) m2 (v2initial)^2 = (1/2) m1 (v1final)^2 + (1/2) m2 (v2final)^2 (1/2) ( .515) (.6679)^2 + (1/2) (515) (0)^2 = (1/2) (.515) (.03735)^2 + (1/2) (.515) (.5649)^2 .115 J should equal .0825 J Kinetic energy should be conserved in an elastic collision. .0825/.115=.718 Unfortunately, only 71.8% of the kinetic energy was conserved, so it is only 71.8% elastic. It is 28.2% inelastic.


 * Inelastic Collision 1**



Momentum

(m1*v1initial) + (m2*v2initial) = (m1*v1final) + (m2*v2final) (0.515)*(.5391) + (0.515)*(0) = (0.515)*(.2541) + (0.515)*(.2572) .278 kg*m/s should equal .263 kg*m/s .263/.278=.947 Only 94.7% of the momentum was conserved.

Kinetic Energy

(1/2) m1 (v1initial)^2 + (1/2) m2 (v2initial)^2 = (1/2) m1 (v1final)^2 + (1/2) m2 (v2final)^2 (1/2) (0.515) (.5391)^2 + (1/2) (0.515) (0)^2 = (1/2) (0.515) (.2541)^2 +(1/2) (0.515) (.2572)^2 .075 J does not equal .034 J .034/.075= .453, 45.3% of the energy was conserved. It is 45.3% elastic It is 54.7% inelastic.


 * Elastic Collision 2**



Momentum

(m1*v1initial) + (m2*v2initial) = (m1*v1final) + (m2*v2final) (1.015)*(.6548) + (0.551*0) = (1.015*.3185) + (0.551)*(.5667) .665 kg*m/s should equal .636 kg*m/s, since momentum is always conserved.

Kinetic Energy

(1/2) m1 (v1initial)^2 + (1/2) m2 (v2initial)^2 = (1/2) m1 (v1final)^2 + (1/2) m2 (v2final)^2 (1/2) (1.015) (.6548)^2 + (1/2) (0.551) (0)^2 = (1/2) (1.015) (.3185)^2 + (1/2) (0.551) (.5667)^2 .218 J should equal .140 J since it is an elastic collision. .140/218= .642 Only 64.2% of the kinetic energy was conserved. The collision was only 64.2% elastic and 35.8% inelastic.


 * Inelastic Collision 2**



Momentum

(m1*v1initial) + (m2*v2initial) = (m1*v1final) + (m2*v2final) (1.015*.5243) + (0.515 * (5.681 x 10^-18) = (1.015*.3343) + (0.515*.3337) .532 kg*m/s should equal .511 kg*m/s, since momentum is always conserved..

Kinetic Energy

(1/2) m1 (v1initial)^2 + (1/2) m2 (v2initial)^2 = (1/2) m1 (v1final)^2 + (1/2) m2 (v2final)^2 (1/2)(1.015)(.5243^2) + (1/2)(0.515)(5.681x10^-18)^2 = (1/2)(1.015)(.3343^2) + (1/2)(0.515)(.3337^2) .1395 J does not equal .085J .085/.1395= .612 61.2% of the kinetic energy was conserved The collision is 61.2% elastic The collision is 38.8% inelastic.