Diffusion vs. facilitated transport
a. if diffusion was the only mode of oxygen transport, how long would it take for a molecule of oxygen to diffuse from your lungs to the most distal part of your body (toes)? assume d = 2.1 x 10-5 cm2/s and work the problem for 1-d, 2-d and 3-d.
b. compare this diffusion time with the amount of time a red blood cell travels from your heart to your big toe.

Modern high speed trains do not have perpendicular expansion gaps where rails are joined end-to-end any more they are mostly welded together but what might happen if there was a spell of particularly hot weather that causes inspection of the tracks?

A)-explain briefly the importance of standards in engineering design. b)- what is patent? c)-explain the relationship between these standards: b.s. and b.s.en d)- in engineering design concepts, types of loads and how they act are important factors. explain.

Acompressor compresses a gas, a pump compresses a liquid. for a given pressure ratio, why does it take more work to compress a gas in a compressor than a liquid in a pump? a)- for a given pressure ratio the average specific volume for a gas is much higher than the average specific volume for a liquid. b)- there is no difference. the only difference is the amount of heat generated (not work) c)- for a given pressure ratio the average volurge for a gas is much higher than the average volume for a liquid. d)-there is no difference