- #1

richengle

- 26

- 1

- Homework Statement
- in an INELASTIC collision, how is momentum conserved, but not energy?

- Relevant Equations
- Cons of Momentum

m1v1+m2v2=m1vs'+m2v2' , if car hits small fluffy object m2, initially v2=0, and v1'=v2' ... so

m1v1=[m1+m2](v2')

but why not energy? Why is there a KElost in Cons of Energy?

Cons of Energy

.5m1v1^2+.5m2v2^2=.5m1v1'^2+.5m2v'2^2 +KElost , and again v2=0, v1'=v2'

.5m1v1^2=.5[m1+m2]v2'^2+KElost

I know you could say deformation, but do you somehow have to take the derrivative of energy [wrt what i dont know] to find a maximum, which is dependent on the initial and final masses and velocities?

m1v1+m2v2=m1vs'+m2v2' , if car hits small fluffy object m2, initially v2=0, and v1'=v2' ... so

m1v1=[m1+m2](v2')

but why not energy? Why is there a KElost?

.5m1v1^2+.5m2v2^2=.5m1v1'^2+.5m2v'2^2 +KElost , and again v2=0, v1'=v2'

.5m1v1^2=.5[m1+m2]v2'^2+KElost

using consv of momentum...

KElost=.5[m1v1^2[1-m1/(m1+m2)] ?

.. and if m1>>m2, this is zero,,, how? Some energy should still be lost?

I know you could say deformation, but do you somehow have to take the derrivative of energy [wrt what i don't know] to find a maximum, which is dependent on the initial and final masses and velocities?

m1v1=[m1+m2](v2')

but why not energy? Why is there a KElost?

.5m1v1^2+.5m2v2^2=.5m1v1'^2+.5m2v'2^2 +KElost , and again v2=0, v1'=v2'

.5m1v1^2=.5[m1+m2]v2'^2+KElost

using consv of momentum...

KElost=.5[m1v1^2[1-m1/(m1+m2)] ?

.. and if m1>>m2, this is zero,,, how? Some energy should still be lost?

I know you could say deformation, but do you somehow have to take the derrivative of energy [wrt what i don't know] to find a maximum, which is dependent on the initial and final masses and velocities?

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