Two ice skaters, Daniel

$($

mass

$7$

$0$

$.$

$0$

$$kg

$)$

$$and Rebecca

$($

mass

$4$

$5$

$.$

$0$

$$kg

$)$

$,$

$$are practicing. Daniel stops to tie his shoelace and, while at rest, is struck by Rebecca, who is moving at

$1$

$3$

$.$

$0$

$$m

$/$

s

$$before she collides with him. After the collision, Rebecca has a velocity of magnitude

$8$

$.$

$0$

$0$

$$m

$/$

s

$$at an angle of

$5$

$3$

$.$

$1$

$$

$$from her initial direction. Both skaters move on the frictionless, horizontal surface of the rink. What is the change in total kinetic energy of the two skaters as a result of the collision?