Quick Bio/Physics Question

[akaMondo]

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Bio:
http://imgur.com/YWfuEFL,nFCUyoe

D? I know A is not true, since arterial blood has higher oxygen content. B and C don't seem right. D deals with chloride shift... would that increase volume of blood cells in the venous system?

Physics:
http://imgur.com/YWfuEFL,nFCUyoe#1
B? I know A isn't right, because the box wouldn't move. D isn't right because conservation of energy. Why wouldn't C be right, though? Work is change in kinetic energy, right? Or is that not taking into account energy dissipated by friction?

 

[athockey7]

i would like to know this as well


for 1) i think i agree with ur answer

for 2) i think B because it has to be greater in order to have translational motion right?
and i think ur reasoning for why C is wrong is correct

 

[The_Sunny_Doc]

I think you guys are right. A, B, and C sound wrong. I'm studying the circulatory system now, too.

Per some journal article:
"As a result of the shift of chloride ions into the red cell and the buffering of hydrogen ions onto reduced haemoglobin, the intercellular osmolarity increases slightly and water enters causing the cell to swell. This can be measured as an increase in mean corpuscular volume (MCV). The reverse process occurs as the red blood cell passes through the lung."

 

[The_Sunny_Doc]

Re the physics question-

The applied force (the person) does more work than the kinetic friction force. All of the work of the person, Fdcostheta, goes into changing the KE of the box. Friction also does work on the box by changing the KE (decreasing it), but kinetic friction force ALSO changes the internal energy of the box by increasing the temperature. Things of how your palms get warmer rubbing them together. Only changing the mechanical energy qualifies as doing work for our purposes.

The mechanical energy is just kinetic energy in this case because the box is on a flat surface.