The speed of the block is given by:

Where,
w: angular speed
r: radius of the circular path.
The angular velocity must be in radians over seconds:

The radius must be in the subway:

Then, the speed is given by:


The tension of the rope is the centripetal force.
By definition, the centripetal force is:

Where,
m: mass of the block in kilograms
Substituting values:

Answer:
its speed and tension on string are:
