If the power ratio of the two machines is 3:4, the ratio of their work in the same time is 0______ The ratio of time required to do the same amount of work is______ ．

If the power ratio of the two machines is 3:4, the ratio of their work in the same time is 0______ The ratio of time required to do the same amount of work is______ ．

∵ the power ratio of the two machines is 3:4, the ratio of work they do in the same time: w1w2 = p1tp2t = p1p2 = 34; the ratio of time they do the same work: t1t2 = wp1wp2 = p2p1 = 43

A rice cooker has two resistance wires in high, middle and low range, and one resistance wire in middle range is 600W, so as to obtain high and low grade electric power

In the middle range, only one resistance wire works
High grade is the parallel operation of two resistance wires
Low grade is two resistance wire series work
In parallel, P = P1 + P2 = 1200W
In series, P = u ^ 2 / (R1 + R2) = 1 / 2 * u ^ 2 / R1 = 300W

The electric power of an electric cooker is 800 watts when it works normally. In physical sense, it means that the electric cooker works normally__________________________________

The power of a rice cooker is 800W when it works normally. In physical sense, it means that the rice cooker consumes 800j per second

When the electric cooker is used in household circuit with power of 800W, what is its resistance? When it is used under 110V voltage, what is its electric power?

(1) The voltage of domestic circuit in our country is 220 V, so r = u & sup2 / P = (220 V) & sup2 / 800 w = 60.5 Ω according to r = u & sup2 / P, so its resistance is 60.5 Ω