Power output of a shaft?

hi guys im new here so please be paitent with me and hopefully ive posted this in the right spot, ok my question is this,
if i have a wind turbine , with blades of 400mm long, 100mm wide at an angle of 45 degrees, and a wind speed of 20 meters/sec what is the power output of the shaft that blades are connected to? what would the output be measured in? and how many rpms would the turbine be spinning? is it even possible to get this info from these parameters?
really sorry about being so vague but its all the info i have, if anyone here can help it would be really appreciated and if possible can you tell me how you came up with the answer, please note that the turbine isnt actually connected to a generator or anything atall.
many thanks in advance