g-LOC in dogfights. When a pilot takes a tight turn at`high speed in a modern fi

Question

g-LOC in dogfights. When a pilot takes a tight turn at`high speed in a modern fighter airplane, the blood pressure at the brain level decreases, blood no longer perfuses the brain, and the blood in the brain drains. If the heart maintains the (hydrostatic) gauge pressure in the aorta at 100 torr (or mm Hg) when the pilot undergoes a horizontal centripetal acceleration of 3.6g, what is the blood pressure (in torr) at the brain, 32 cm radially inward from the heart? The perfusion in the brain is small enough that the vision switches to black and white and narrows to ''tunnel vision'' and the pilot can undergo g-LOC (''g-induced loss of consciousness''). Blood density is 1.06 × 103 kg/m3.

Explanation / Answer

Given that if the heart maintains guage pressure is Pheart = 100 torr The pilot undergoes acceleration of a = 3.6g The inward acceleration can be treated from the pilots reference frame as though it is an outward gravitational acceleration aganist which the heart must push the blood thus         a = 3.6( 9.8 m/s2 )             = 35.28 m/s2 Blood pressure at the brain is PBrain = Pheart - a r              = 100 torr - 1.06*103 kg / m3 ( 35.28 m/s2 ) ( 0.32 m) ( 1 torr / 133 Pa)              = 10 torr The inward acceleration can be treated from the pilots reference frame as though it is an outward gravitational acceleration aganist which the heart must push the blood thus         a = 3.6( 9.8 m/s2 )             = 35.28 m/s2 Blood pressure at the brain is PBrain = Pheart - a r              = 100 torr - 1.06*103 kg / m3 ( 35.28 m/s2 ) ( 0.32 m) ( 1 torr / 133 Pa)              = 10 torr

Related Questions

Navigate

• Browse (All)
• Browse G
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.