How can I solve for the mass of the first car in an elastic collision problem?

Thread starter tony873004
Start date May 3, 2005
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Algebra Collision Elastic Elastic collision

AI Thread Summary

To solve for the mass of the first car (m1) in an elastic collision problem, the relevant equations include the conservation of momentum and kinetic energy principles. The equation m1 = (-u2 * m2) / (u2 - 2v1) is derived from rearranging the momentum conservation equation. The discussion highlights the importance of correctly applying these principles to isolate m1. The solution provided by a user named whozum was confirmed to be effective. This approach clarifies how to manipulate the equations to find the desired mass in collision scenarios.

May 3, 2005

tony873004

Science Advisor

Gold Member

In an elastic collision problem, I'm supposed to solve for the mass of the 1st car (m1). I get stuck here. How do I re-write this to solve for m1?

u_2=\frac{2*m_1v_1}{m_1+m_2}

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May 3, 2005

whozum

Thats the equation for an inelastic collision, but

u_2m_1+u_2m_2-2m_1v_1 = 0

u_2m_1 - 2m_1v_1 = -u_2m_2

m_1(u_2 - 2v_1)= -u_2m_2

m_1 = \frac{-u_2m_2}{u_2-2v_1}

May 3, 2005

tony873004

Science Advisor

Gold Member

Thanks, whozum. That worked !

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