If the thickness of the coating is 2.5 mm and it has an initial uniform temperature of 200ºc, how long will it take for the surface to achieve a safe-to-touch temperature of 38ºc if the convection coefficient is 200 w/m2·k? what is the corresponding value of the interface temperature? the thermal conductivity and diffusivity of the plastic are 0.25 w/m·k and 1.20 × 10-7 m2/s, respectively.

Humidity is to blame for that muggy, steamy feeling you experience on some hot summer days. what gas in the atmosphere causes humidity? a) oxygen b) hydrogen c) nitrogen d) water vapor

Contains chemical energy. a. heat b. light c. natural gas

Along wire of diameter 1 mm is submerged in an oil bath of temperature ∞ 31°c. the wire has an electrical resistance per unit length of 0.01 ω/m. if a current of 103 a flows through the wire and the convection coefficient is 500 w/m2·k, what is the steady-state temperature of the wire? from the time the current is applied, how long does it take for the wire to reach a temperature that is within 1°c of the steady-state value? the properties of the wire are 8000 kg/m3, 500 j/kg·k, and 20 w/m·k.