- #1

B3NR4Y

Gold Member

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## Homework Statement

Two objects of inertias m

_{1}and m

_{2}start from rest and then interact with each other (assume neither is interacting with any other object).

What is the ratio of their kinetic energies at any instant?

## Homework Equations

[itex] \frac{K_{1}}{K_{2}} = ? [/itex]

The first part of the equation asked me to relate velocities to masses and I got a correct answer of

[itex]\frac{v_{2x}}{v_{1x}} = -\frac{m_{1}}{m_{2}} [/itex]

## The Attempt at a Solution

I know that Kinetic Energy is half of the mass times the square of the velocity, and that's where my attempt falls apart, because I have to express the answer in terms of m

_{1}and m

_{2}, but they're already in KE so I don't understand how that works out. My answer I got was

[itex]\frac{K_{1}}{K_{2}} = \frac{m_{2}}{m_{1}} [/itex]

Without the negative cause it is the square of the velocity and that will eliminate any negatives. Please help.