The load across a 120-V power supply consists of three resistances are R1 = 10 Ω, R2 = 30 Ω, and R3 is unknown. If R2 has a difference of potential of 45 V across it, find the other voltage drops across the other resistors, the current through each resistor, and R3.

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

Why should seat belts not be mandatory quick plz

Your town is considering building a biodiesel power plant describe at least two advantages and two disadvantages