In Millikan's experiment in the figure below, an oil droplet of mass 4.45 fg has an excess charge of five electrons. An electric field has been applied,
and the droplet is levitating. What is the magnitude of the electric field?
(Units: N/C) note: 1fg = 10^-15g=10^-18kg

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.