An elevator cabin is moving up, being pulled by an elevator cable under a tension of 8000N. mThe combined mass of four people in an elevator is 180 kg while the mass the elevator cabin itself is 195 kg. Find the acceleration of elevator cabin in the system of coordinates that has a positive vertical direction upward.

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?

An object's buoyant force and weight mean the same thing.a. trueb. false

Suppose a wire with a current is pushed upward by a magnetic field. how would the wire move if the direction of the current reversed? explain your answer.