the electrical energy used to pump the water up to a mountain lake is 1.2 x 10 to the power 12 J only 6.2 x 10 to the power 11 J of electrical energy is generated when the water is released calculate the efficiency of this energy storage scheme

The sun generates both mechanical and electromagnetic waves. which statement about those wave is true?

Which of these is constant for all types of electromagnetic radiation in a vacuum? select one: a. wavelength b. frequency c. photon energy d. amplitude e. velocity

Global climatic patterns are changing because of the melting of polar ice caps. the melting of polar ice caps is an example of the interaction between the atmosphere and cryosphere cryosphere and geosphere hydrosphere and geosphere biosphere and cryosphere