To calculate the acceleration of the skater on the rough ice, we use the equation

Here, u is initial speed when she hits the patch of ice and its value is 10 m/s and v is final speed when she left the patch of ice and its value is given 7.0 m/s and s is the width of patch of ice and its value is 5.0 m.
Substituting these values in above equation we get,
.
Thus, the acceleration of skater on the rough ice is
