The SYSTOLIC pressure in a major artery is measured at 115 mmHg. What is the net force on a 1 cm2 section of the artery wall if the absolute pressure in the tissue outside the arterial wall is 108.6 kPa?
115 mm = 15.332 kPa
1 atm is about 101.3 kPa
and we are about
101.3 + 15.3 = 116.6 kPa absolute
so difference in presuure across wall
= 116.6 - 108.6 = 8 kPa = 8000 Pascals or Newtons / m^2
1 cm^2 = 10^-4 m^4
so our force is
8000 * 10^-4 = 0.8 Newtons
Thank you so much.
You are welcome.
excuse me, why did you add atm pressure to 15.3? your answer is true 100 present, but I did not understand this point.
Yes I did because the meters used measure relative, not absolute, pressure. (Relative is above one atmosphere)