In a fluorescent tube of diameter 3 cm, 3 times 1018 electrons and 0.75 times 1018 positive ions (with a charge of +e) flow through a cross-sectional area each second. What is the current in the tube?

Achild throws a ball with an initial speed of 8.00 m/s at an angle of 40.0° above the horizontal. the ball leaves her hand 1.00 m above the ground. how long is the ball in flight before it hits the ground?

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?

Does anyone have the answers to online physics course plato course physics, semester a v3.0