posted by Becky .
Kenya finally loses her cool and punches her teacher. The teacher weighs 85 kg. He sees the punch coming and begins to back up at a speed of 0.60 m/s. After Kenya clocks him, he is moving backwards at a speed of 0.82 m/s. If the contact time of Kenya's fist to the teachers nose was 0.075 s, what average force did her punch have?