- #1

BrainMan

- 279

- 2

## Homework Statement

A 90-kg halfback running north with a speed of 9 m/s is tackled by a 120-kg opponent running south with a speed of 3 m/s. If the collision is perfectly inelastic and head-on, calculate. (a) the velocity of the players just after the tackle and (b) the total energy lost as a result of the collision.

## Homework Equations

m

_{1}v

_{1i}+ m

_{2}v

_{2i}= (m

_{1}+ m

_{2})v

_{f}

## The Attempt at a Solution

I plugged the masses and velocities into the equation for perfectly inelastic collisions and solved for v

_{f}. I got 5.57 m/s and the answer is 2.14 m/s.