What is the wavelength of a 2.8 mhz ultrasound wave traveling through aluminum?

Your 249 ml cup of coffee is too hot to drink when served at 82 degree celsius. what is the mass of an ice cube taken from a -21 degree celsius freezer, that will cool your coffee to a pleasant 54 degree celsius. specific heat of the water is 4190 j/kg c, specific heat of ice is 2090 j/kg c, heat of fusion of ice is 3.33 x 10^5 j/kg

Ahydroelectric plant takes energy from water and turns it into electrical energy. what are the transformations of energy in the water molecules that are used in the process of generating electricity this way?

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?