Book edition 10th Edition

Author(s) David Halliday

Pages 1328 pages

ISBN 9781118230718

Answers without the blur.

Just sign up for free and you're in.

Short Answer

Giraffe bending to drink. In a giraffe with its head $2.0 m$ above its heart, and its heart $2.0 m$ above its feet, the (hydrostatic) gauge pressure in the blood at its heart is250 $t o r r$ . Assume that the giraffe stands upright and the blood density is $1.06 \times 10^{3} k g / m^{3}$ . (a) In $t o r r$ (or role="math" localid="1657260976786" $m m H g$ ), find the (gauge) blood pressure at the brain (the pressure is enough to perfuse the brain with blood, to keep the giraffe from fainting). (b) $t o r r$ In (or $m m H g$ ), find the (gauge) blood pressure at the feet (the pressure must be countered by tight-fitting skin acting like a pressure stocking). (c) If the giraffe were to lower its head to drink from a pond without splaying its legs and moving slowly, what would be the increase in the blood pressure in the brain? (Such action would probably be lethal.)

Gauge pressure at the brain of giraffe is $94 t o r r$
Gauge pressure at the feet of giraffe is $406 t o r r$
Increment in pressure is 312 $t o r r$

See the step by step solution

Step by Step Solution

TABLE OF CONTENTS :

TABLE OF CONTENTS

The given data

Density of blood, $p = 1.06 \times 10^{3} k g / m^{3}$
Heart pressure, $p = 250 t o r r$

Understanding the concept of gauge pressure

Use the formula for gauge pressure, which depends on density, height, and acceleration due to gravity. Gauge pressure is that, which is exerted by a fluid at any point of time at equilibrium due to the force applied by gravity.

Formula:

Pressure applied on a fluid surface, $p = p g h$

Net pressure applied on a body, $∆ p = p_{2} - p_{1}$

a) Calculation of pressure at brain

From equation (ii), the pressure at brain can be given as:

$p_{b r a i n} = p_{h e a r t} - p g h = 250 - 1.06 \times 10^{3} \times 9.8 \times 2 \times \frac{1 t o r r}{133.33 P a} (∵ 1 t o r r = 133.33 P a) = 94.2 t o r r$

The pressure at brain is 94.2 torr.

b) Calculation of pressure at feet

From equation (ii), the pressure at brain can be given as:

$P_{f e e t} = P_{h e a r t} + p g h (∵ here pressure is total pressure) = 250 + 1.06 \times 10^{3} \times 9.8 \times 2 \times \frac{1 t o r r}{133.33 P a} (∵ 1 t o r r = 133.33 P a) = 405.8 t o r r$

The pressure at feet is 405.8 torr.

c) Calculation of increment in pressure

From equation (ii), the net pressure between brain and feet can be given as:

$∆ p = p_{b r a i n} - p_{f e e t} = 405.8 - 94.2 = 311.6 t o r r$

Hence, the increased value of pressure is 311.6 torr.

Find Study Materials for

Create Study Materials

Select your language

Fundamentals Of Physics

Answers without the blur.

Short Answer

Step by Step Solution

The given data

Understanding the concept of gauge pressure

a) Calculation of pressure at brain

b) Calculation of pressure at feet

c) Calculation of increment in pressure

Most popular questions for Physics Textbooks

Want to see more solutions like these?

Recommended explanations on Physics Textbooks

Select your language

Fundamentals Of Physics

Answers without the blur.

Short Answer

Step by Step Solution

The given data

Understanding the concept of gauge pressure

a) Calculation of pressure at brain

b) Calculation of pressure at feet

c) Calculation of increment in pressure

Most popular questions for Physics Textbooks

Want to see more solutions like these?

Recommended explanations on Physics Textbooks

Work Energy and Power

Radiation

Astrophysics

Physics of Motion

Scientific Method Physics

Famous Physicists

Fluids

Torque and Rotational Motion

Nuclear Physics

Fields in Physics

Measurements

Space Physics

Electricity

Physical Quantities and Units

Medical Physics

Electrostatics

Further Mechanics and Thermal Physics

Mechanics and Materials

Engineering Physics

Energy Physics

Force

Particle Model of Matter

Waves Physics

Magnetism

Modern Physics

Atoms and Radioactivity

Dynamics

Electricity and Magnetism

Conservation of Energy and Momentum

Fundamentals of Physics

Kinematics Physics

Circular Motion and Gravitation

Linear Momentum

Rotational Dynamics

Oscillations

Translational Dynamics

Geometrical and Physical Optics

Thermodynamics

Magnetism and Electromagnetic Induction

Electromagnetism

Electric Charge Field and Potential

Turning Points in Physics