What is the exact meaning of croos section and cross sectional area of a conductor?

Which is not one of the major climate zones? question 3 options: rain forest polar tropical temperate

Awave with a frequency of 500 hz is traveling at a speed of 100 m/s.what is the wavelength?

The amount of heat required to change liquid water to vapor at its boiling temperature is 2256 kj/kg. the amount of heat required to change liquid mercury to its vapor state at its boiling temperature is 295 kj/kg. one kg of each substance is currently at its boiling point. how will the amount of thermal energy required to change each substance from a liquid to a gas differ?