Rotation Dynamics mastering physics 10.32

[wku_tops]

An airplane propeller is 2.08 m in length (from tip to tip) and has a mass of 117 kg. When the airplane's engine is first started, it applies a constant torque of 1950 Nm to the propeller, which starts from rest.

How much work in joules is being done after 5 revolutions?

This is what I did: (1.04*1950)*(5*2*pi). Mastering physics says it is close, but not correct.

 

[wku_tops]

figured that out: (1950)*(5*2pi)
Now I need to calculate the average power. power=T_z*w_z
=1950 Nm *53.9 rads/s.

mastering physics says this is incorrect. Any ideas?