Communication with submerged submarines via radio waves is difficult because seawater is conductive and absorbs electromagnetic waves. penetration into the ocean is greater at longer wavelengths, so the united states has radio installations that transmit at 76hz for submarine communications. what is the approximate wavelength of those extremely low-frequency waves? 500 km1000 km2000 km4000 km

Jackson is designing a new heater, and he wants to experiment with different thermally conductive materials. which of these materials would be useful in conducting heat?

Glass has a hardness that is in the middle of the hardness scale. what is the hardness of glass?

Which best describes the first law of thermodynamics as compared to the second law of thermodynamics? a. the first law describes how thermal energy is conserved but not the direction it moves. b. the first law describes the direction thermal energy moves but not how it is conserved. c. the first law describes how thermal energy can be created but not how it can be destroyed. d. the first law describes how thermal energy can be destroyed but not how it can be created.