3. Consider the arrangement shown on the given schematic a linear heat source From the heat equation, the following formula is obtained for a linear heat source (thin, long wire) by an approximate series expansion, with which the temperature T at a distance r from the heat source at a certain time t can be determined as: sample of material Trit) 9L fik [In (1998) ] (1) where k = thermal conductivity of the material, az is heat output from the k linear heat source [W-m*'), a = is thermal diffusivity [ms-'], y = 0.577 pcp is Euler's constant. Attempt to assess whether the equation (1) can be used for the determination of the thermal conductivity (or this possibility should be rejected due to the certain objections). Assume you possess the temperature probe (say, the thermocouple) which can be positioned at the specified distancer from the linear heat or source. (30%)