The relationship between
and
is given by the law of laminar flow is
.
Where
is a viscosity of blood and
is pressure difference between ends of tube.
Here
and
are constants.
(a)
\Velocity is
.
Here
dynes/cm2,
,
cm, and
cm.
Substitute above values in
.
.
When
cm :

.
When
cm :

.
When
cm :

.
(b)
\Velocity gradient is instantaneous rate of change velocity with respect to
.
Velocity gradient
.

Differentiate on each side with respect to
.

Velocity gradient
.
Find Velocity gradient when
:
Substitute
,
,
and
in
.

.
Find Velocity gradient when
:
Substitute
,
,
and
in
.

.
Find Velocity gradient when
:
Substitute corresponding values in
.

.
(c)
\From the part (a) it is observed that velocity is greatest at
, which means at the center.
and velocity gradient is greatest at
.
(a)
,
and
.
(b)
, 
and
.
(c) Velocity is greatest at
, which means at the center and velocity gradient is greatest at
.