Answer:
Straight line in the direction of the tangential velocity the ball had at the moment the string broke
Explanation:
After the string breaks, the ball now disconnected from the centripetal force that was exerted via the string, continues its travel in a straight line in the direction of the tangential velocity it had at the moment the string broke.
v^2-u^2=2 x a x d
25^2-0^2=2 x a x 70
625-0=140 x a
625=140a
a=625/140
a=4.46 m/s^2
im not very sure but i think this is how you do this
D will hit last because if air resistance is null then the only force enacting on the balls is the force of gravity. Force of Gravity has an acceleration of 9.81 ms^2 and so every ball had the same acceleration and ball D is the furthest away from the floor.