Answer:
Tangential Velocity = 30.24 m/s
Step-by-step explanation:
Given that,
Mass of ball, m = 0.04 Kg
Length of the string, r = 0.70 m
Acceleration of the ball, a = 43.2 m/s²
The tangential velocity of ball, V = ?
The centripetal force is given by the relation
 Fc = mV²/r newton
where, m - mass of body
 V - tangential velocity of body
 r - radius of the trajectory
Force applied on the ball to rotate on a circular path
 F = m x a newton
The applied force is equal to centripetal force.
So, equalizing the force equations
 m x a = m V²/r
Therefore
 V² = a x r
 V = 

Substituting the values
 V = 

 V = 30.24 m/s
So, the tangential velocity of the ball is 30.24 m/s