Answer:
8 m/s²
Step-by-step explanation:
Centripetal acceleration formula:
- a = v²/r 
- where v = velocity and r = radius 
As you can see, the mass of the yo-yo is not relevant to this problem. 
We are given that the velocity of the yo-yo is 4 m/s.
The radius of the circle formed by the yo-yo on a 2-meter long string is 2 meters.
Substitute these known values into the equation.
- a = (4)²/2 
- a = 16/2 
- a = 8 
The centripetal acceleration of the yo-yo is 8 m/s².