posted by Sabrina on .
A speed skater moving across frictionless ice at 9.0 hits a 5.1 -wide patch of rough ice. She slows steadily, then continues on at 6.4 .
What is her acceleration on the rough ice?
a = (V^2-Vo^2)/2d.
a = (40.96-81)/10.2 = -3.93 m/s^2.
"a" is negative because she was slowing down.