A hot steam pipe having an inside surface temperature of 250C has an inside diameter of 9 cm and a wall thickness of 6.5 mm. It is covered with a 10-cm layer of insulation having k =0.5 W/m· •C, followed by a 4-cm layer of insulation having k =0.25W/m •C. The outside temperature of the insulation is 23°C. Calculate the heat lost per meter of length. Assume k =43 W/m: •C for the pipe and the interface temperatures.

A radioactive isotope has an unknown half-life. Initially, there was 10 mg of the isotope in the sample. After 90 minutes, 8.2 mg remained. a.) Determine a base e function to model the amount of isotope that remains after t hours.   b.) How quickly is the amount of isotope remaining changing when 3 mg the original amount remains? Round to 1 decimal place.

8:34 PM Fri 5 May K 00 19CAPE10...0.. (b) Lo (i) (ii) X 19CAPE10200... X 1.82×10 18CAPE10200... -3 - 19CAPE102002s2 ✓ X 18CAPE10200.. X T @*** Answers to th.. O 0·013x = X Lecture 1 X 田 How long will it take until 99% of the reactant have reacted? 36% CAPE 1020 En. = 0'14x fac 2 600 s after initiation of a first order reaction 48.5% of the initial reactant concentration remains present. What is the rate constant for this reaction?

Where do you get C=p/M?