Amagnet is hung by a string and then placed near a wire as shown. when the switch is closed, the magnet rotates such that the end of the magnet moves as indicared by the arrows

Aloaded 355 kg toboggan is traveling on smooth horizontal snow at 4.00 m/s when it suddenly comes to a rough region. the region is 6.60 m long and reduces the toboggan's speed by 1.00 m/s . what average friction force did the rough region exert on the toboggan?