Answer:
Direction of force towards the center and string apply the force.
Step-by-step explanation:
Lets take
Mass of yo-yo =m
Length of string = L
Angular speed = ω
The radial acceleration a = ω² L
Then the radial force on the yo yo given as
F = m ω² L
Then this radial force act towards the center of the circle formed by yo- yo.The force exerted by string.
So the direction of force towards the center and string apply the force.