Yo-yo trick A yo-yo rests on a horizontal table. The yo-yo is free to roll but frict...

Yo-yo trick A yo-yo rests on a horizontal table. The yo-yo is free to roll but friction prevents it from sliding. When the string exerts one of the following tension forces on the yoyo (shown in Figure P8.71), which way does the yo-yo roll? Try the problem for each force: (a) and . [Hint: Think about torques about a pivot point where the yo-yo touches the table.]