- #1

Amarillo99

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## Homework Statement

I'm trying to find the coefficient of restitution (COR) and energy loss upon impact of a bouncing ball, and I'm trying to understand how these relate to each other.

## Homework Equations

COR=sqrt(2gh/2gH)

suvat equations (possibly)

1/2mv^2=mgH (using m=0.0585kg, g=9.8)

energy transfer efficiency = (useful output ÷ total input ) × 100

## The Attempt at a Solution

In my case of a ball released from 1.2m then bouncing to 0.64m, COR=sqrt(2gh/2gH) = 0.73 (fairly elastic). I know that COR is a ratio of the ball velocity before/after impact, therefore also of the kinetic energy before/after. Now doesn't this mean that the final velocity/kinetic energy is 73% of the original?

I'm struggling to verify this because I can't measure the kinetic energy after the bounce. The suvat equations assume constant acceleration or time so I don't think I can use those. Given that I know the final velocity upon bouncing using mgH=1/2mv^2, v = sqrt(23.52)m/s, and I know the bounce height (0.64m) is there another way?