If the coil resistance value of a motor is R and it turns normally in the circuit with voltage of u, and the current intensity passing through the motor is I, then the heating power of the motor coil is______ The power of the motor to do external work is______ ．

If the coil resistance value of a motor is R and it turns normally in the circuit with voltage of u, and the current intensity passing through the motor is I, then the heating power of the motor coil is______ The power of the motor to do external work is______ ．

If the heating power of the motor P = I2R and the total power consumed by the motor P = UI, then the power for external work is: P = ui-i2r, so the answer is: I2R, ui-i2r

If the time ratio of a and B is 3:4 and the power ratio is 2:3, then their work ratio is ()
A. 1：2B. 2：1C. 3：4D. 2：3

∵ P = wt ∵ w = Pt, ∵ the ratio of their work: w a W B = p a t a P B T B = 2 × 33 × 4 = 12

If the power ratio of the two machines is 3:4 and the mechanical efficiency ratio is 4:3, the mechanical work ratio at the same time is:
————When they do the same useful work, the ratio of time is——————

The power is 3; 4
The total work done at the same time is 3; 4, that is, the ratio of mechanical work done at the same time is 3; 4
The mechanical efficiency is 4; 3
Then the effective work done in the same time is 1; 1

If the ratio of work done by two machines is 3:2 and the ratio of time is 3:4, then the ratio of power is (). If they complete the same work, the ratio of time is ()

If the work ratio of two machines is 3:2 and the time ratio is 3:4, the power ratio is (2:1). If they complete the same work, the time ratio is (1:2)