A cross-country skier is skiing along at a zippy \(8.0 \mathrm{~m} / \mathrm{s}\). She stops pushing and simply glides along, slowing to a reduced speed of \(6.0 \mathrm{~m} / \mathrm{s}\) after gliding for \(5.0 \mathrm{~m}\). What is the magnitude of her acceleration as she slows?