Copper is a very good conductor of heat and thus not a very good insulator. it has a thermal conductivity of 398 w/(m-°c). a square cu plate with cross-sectional area 0.15 ×10-2 m2 is sandwiched between two isothermal plates, each of which is at a different temperature. the cu plate is fully insulated along its exposed edges so that the only significant heat flux is directed through the thickness of the plate. one side of the cu plate is maintained at 190.8°c by an electric energy supply of 1,086 watts. assuming steady-state heat flow conditions, how thick, in mm, must this cu plate be so that the temperature on the other side of the cu plate does not exceed 24°c ?

The Cu plate must be at least 91.69 mm thick

Explanation:

To solve this problem we need to use the Fourier's law for thermal conduction:

Here, we must solve the equation for d, assuming that the maximum possible temperature of the other side of the plate is 24°C:

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

layers of the earth affect the waves and these effects are seen on instruiments such as seimometers