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 1590Nm to the propeller, which starts from rest.

Question I:

What is the average power output of the engine during the first 5.00 rev?

Question II:

What is the instantaneous power output of the motor at the instant that the propeller has turned through 5.00 rev?

I've already solved for the angular accelleration (after 5 revolutions) which is alpha, angular speed omega (after 5 revolutions), and work after 5 revolutions W, moment of inertia 42.18kg*m^2.

For the last two parts I've tried to solve using P=torque+angular velocity .... that turned out to be wrong. Then I tried using P=Change in work/change in time but that failed. So now I'm a little at a loss. Is there any suggestions where to try next?

I figured it out, my methods were correct...... my ending units were wrong! @_@

Question I:

What is the average power output of the engine during the first 5.00 rev?

Question II:

What is the instantaneous power output of the motor at the instant that the propeller has turned through 5.00 rev?

I've already solved for the angular accelleration (after 5 revolutions) which is alpha, angular speed omega (after 5 revolutions), and work after 5 revolutions W, moment of inertia 42.18kg*m^2.

For the last two parts I've tried to solve using P=torque+angular velocity .... that turned out to be wrong. Then I tried using P=Change in work/change in time but that failed. So now I'm a little at a loss. Is there any suggestions where to try next?

I figured it out, my methods were correct...... my ending units were wrong! @_@

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