Suppose that the aorta has a radius of about 1.25 cm and that the typical blood velocity is around 30 cm/s
and that it has an average density of 1050 kg/m^3.
(a) What is the average blood velocity in the major
arteries if the total cross-sectional arca of the major
arteries is 20 cm^2,
(b) What is the total flow rate?
(c) If the blood in the circulatory system goes through
the capillaries, what is the total cross-sectional area
of the capillaries if the average velocity of the
blood in the capillaries is 0.03 cm/s?
(d) If a typical capillary has a cross-sectional area of 3
X 10^-11 m^2. about how many capillaries are there
in the human body?
(e) What is the kinetic energy per unit volume for blood
in the aorta, the major arteries, and the capillaries?
(f) If a capillary has an average length of 0.75 mm
what is the average time that a red blood cell
remains in a capillary?

American eels (anguilla rostrata) are freshwater fish with long, slender bodies that we can treat as uniform cylinders 1.0 m long and 10 cm in diameter. an eel compensates for its small jaw and teeth by holding onto prey with its mouth and then rapidly spinning its body around its long axis to tear off a piece of flesh. eels have been recorded to spin at up to 14 revolutions per second when feeding in this way. although this feeding method is costly in terms of energy, it allows the eel to feed on larger prey than it otherwise could. 1.a field researcher uses the slow-motion feature on her phones camera to shoot a video of an eel spinning at its maximum rate. the camera records at 120 frames per second. through what angle does the eel rotate from one frame to the next? 2. the eel is observed to spin at 14 spins per second clockwise, and 10 seconds later it is observed to spin at 8 spins per second counterclockwise. what is the magnitude of the eels average angular acceleration during this time? 3. the eel has a certain amount of rotational kinetic energy when spinning at 14 spins per second. if it swam in a straight line instead, about how fast would the eel have to swim to have the same amount of kinetic energy as when it is spinning? 4.a new species of eel is found to have the same mass but one-quarter the length and twice the diameter of the american eel. how does its moment of inertia for spinning around its long axis compare to that of the american eel?

For general projectile motion, when the projectile is at the highest point of its trajectory, its acceleration is zero? a)the horizontal and vertical components of its velocity are zero. b) its velocity is perpendicular to the acceleration. c)the horizontal component of its velocity is zero. d)its velocity and acceleration are both zero.

What is the measurement of how fast an object moves relative to a reference point?