Amotorcycle is moving at a constant speed of 45km/h how long does it take the motorcycle to travel a distance of 20km?

This is how zirconium appears in the periodic table. rounded to the nearest whole number, how many electrons are in an atom of zirconium?

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?

Iwill give 30 points to whoever answers ! what is the formula for actual mechanical advantage and ideal mechanical advantage?