Calcula la fuerza de fricción que mantiene a una persona de 75 kg sentada en la orilla de una plataforma giratoria horizontal, cuando la persona se encuentra a 2 m del
centro de la plataforma y tiene una rapidez tangencial de 3 m/s. Ahora calcula el
momento angular.

An ice-making machine inside a refrigerator operates in a carnot cycle. it takes heat from liquid water at 0.0 degrees celsius and rejects heat to a room at a temperature of 19.2 degrees celsius. suppose that liquid water with a mass of 76.3kg at 0.0 degrees celsius is converted to ice at the same temperature. take the heat of fusion for water to be l_f = 3.34*10^5 j/kg.how much energy e must be supplied to the device? express your answer in joules.