Consider a thin suspended hotplate that measures 0.2 m × 0.2 m. the isothermal plate has a mass of 3.75 kg, a specific heat of 2770 j/kg·k, and a temperature of 275°c. the ambient air temperature is 25°c and the surroundings temperature is 25°c. if the convection coefficient is 6.4 w/m2·k and the emissivity of the plate is ɛ= 0.42, determine the time rate of change of the plate temperature, d⁢t/d⁢t , when the plate temperature is 275°c. evaluate the magnitude of the heat losses by convection and by radiation.