Sphere A has a mass of 4.2 x 10-2 kg and is tethered to a wall by a thin thread. Sphere A has an
excess of 1.2 x 1012 electrons. Sphere B has a deficit
of 3.5 x 1012 electrons and is 0.23 m from sphere A.
Determine the angle between the thread and
the wall.

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?

What is the average speed of a car that travels 40mph for 1 hour and 60 mph in another hour will mark brainliest

Often called simply "velocity," this is the velocity of an object at a particular moment in time.