Heat and Mass Transfer

Heat transfers from an area of ____temperature to an area of ___ temperature.

• high to low

• low to high

• high to high

• t can travel high to low and low to high.

Warm air is __________ dense than cold air and rises creating convection currents.

• more

• less

Transfer of thermal or heat energy through "touch"

• conduction

• convection

• radiation

Fourier law of conduction

• KAdT

• KLdT/dX

• -KAdT/dX

Internal Thermal Resistance (R) formula for single slab is

(a)  

where L = 0.25 m and K= 387.6 W/mk, find Q in W/m²

• 0.155 x 10⁵

• 15.55 x 10³

• 0.155 x 10³

• 155 x 10³

What is the value for R_BC

• 0.2343

• 0.1461

• 0.2545

• 0.4245

What is the Rbc formula in this diagram???

• Rbc = Rb + Rc

• 1/Rbc = 1/Rb + Rc

• 1/Rbc = 1/Rb + 1/Rc

Near the ceiling of a room the air is warmer. The warm air rises because of...

• conduction

• convection

• radiation

A huge rock at the state park gets really hot during the day because of

• conduction

• convection

• radiation