Thermocouples attached to a truncated conical roller bearing

Thermocouples attached to a truncated, conical roller bearing show that the temperature profile and heat flow rate are:

q = 7500 W

a. What is the thermal conductivity as a function of x?

b. What is the heat flux at x = 0 ?x = .2?

c. Where is the heat flux, highest (0 < x < 0.2) ?

Q = kA(dT/dx)

dT/dx = -1350 + 900x - 1350x²

Therefore 7500 = (0.4-0.4x)(-1350+900x - 1350x²)k

Therefore k = 13.263/(x - 1)(3x²- 2x + 3)

Using the above equations heat flux at x = 0 and 0.2 can be obtained