Q1. A speed skater moving across frictionless ice at 10 m/s hits a 5 m wide patch of rough ice. She slows steadily, and next continues on at 5.8 m/s. What is her acceleration on the rough ice?
Q2. Two students are on a balcony 18.30 m above the street. One student throws a ball, b1, vertically downward at 16.80 m/s. At the same instant, the other student throws a ball, b2, vertically upward at the same speed. The second ball just misses the balcony on the way down. What is the difference of time balls spend in the air?