Some organisms, like the platypus, are difficult to classify as they have characteristics which fall intæ multiple categories. Which characteristics of a platypus would lead scientists to classify them as mammals?
A
presence of a beak and claws
B
lay eggs and have webbed feet
live in the water and have lungs,
D
have glands that produce milk for their young and hair

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.