1. The problem statement, all variables and given/known data The yo-yo has a mass of .2kg and is attached to a sting .8 m long. If the yo-yo makes a complete circular revolution each second, what tension must exist in the string? Can anyone please show me how to do this. thanks. 2. Relevant equations F+t=ma fc equations a=f/m 3. The attempt at a solution they're so wrong, they wouldn't help.