How Fast Must Turbine Blades Spin to Store Energy?

AI Thread Summary
The discussion focuses on calculating the angular velocity required for two 15.0 m long steel turbine blades to store 1.00 MJ of energy using tidal movements. The blades are modeled as thin uniform bars, with a diameter of 25.0 cm and a steel density of 7800 kg/m^3. Participants are encouraged to reference equations of motion and moments of inertia to aid in their calculations. The conversation emphasizes ignoring frictional drag from seawater in the energy storage calculations. Understanding rotational kinetic energy is crucial for solving the problem effectively.
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Angular Velocity Question?

In March 2004, a British company successfully tested a power system to tap the energy of ocean tides. The energy will be stored in an underwater turbine consisting of two metal blades, each 15.0 m long. The movement of the water due to the tides will give kinetic energy to the turbine blades, causing them to spin. In the calculations that follow, ignore any frictional drag due to the seawater.

If we model each of these two blades as a thin uniform steel bar 15.0 m long and 25.0 cm in diameter, at what rate rad/s and rpm must they spin for the turbine to store 1.00 MJ of energy? The density of steel is 7800 kg/m^3 . (Recall that density is equal to an object's mass divided by its volume.)

How do i solve this?? THANKS!
 
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