BIOL 325 MIDTERM 2 QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS | NEW
UPDATE 2025-2026
Venturi effect - ANSWERS reduction in pressure resulting from fluid flowing
through/over a constricted section
pitot tube - ANSWERS measures velocity by converting kinetic energy into
pressure energy and displacing fluid in an attached manometer (simple pitot tube)
can combine pitot tube with second tube that has a hole perpendicular to flow
which allows static pressure to be measured at the other side of the manometer.
the change of height in the fluid of the manometer represents dynamic pressure
only
why does a fluid appear to flow against a pressure gradient - ANSWERS the
openings in the pipe only show static pressure. If a pitot tube is added it measures
static pressure and dynamic pressure and balances out the pressures so the fluid
is flowing down a pressure gradient. The constricted section of a pipe has higher
dynamic pressure due to it flowing at a higher velocity (Pdyn = 1/2pv^2)
how do birds use pitot tubes - ANSWERS they have a static port and
stagnation point directly facing fluid flow. Their nostril pitot tubes sense dynamic
pressure only and therefore different airspeeds which allows them to dynamically
soar using wind speed above the waves.
laminar vs turbulent flow - ANSWERS laminar
- reversible and reproducible
, - ordered
- even velocity gradient
- no mixing
turbulent
- irreversible and non-reproducible
- disordered
- efficient mixing
- erratic flow streams
reynolds number - ANSWERS the tendency of a fluid to flow in a laminar or
turbulent manner depending on viscous force (laminar) and inertial force
(turbulent), ratio of inertial force to friction force
viscous forces - ANSWERS due to fluid shearing over object, fluid exerts a force
on the object due to its viscosity and the shearing in the velocity gradient (μvS/l)
tangential to the objects surface
inertial forces - ANSWERS due to fluid colliding with an object, exerts a force
proportional to density, velocity and surface area of object (1/2ρSv^2) normal to
the objects surface
shift Re to being more turbulent - ANSWERS increasing velocity, increasing
characteristic length, having fluid with a higher density
shift Re to being more laminar - ANSWERS increasing fluid viscosity
ANSWERS WITH COMPLETE SOLUTIONS | NEW
UPDATE 2025-2026
Venturi effect - ANSWERS reduction in pressure resulting from fluid flowing
through/over a constricted section
pitot tube - ANSWERS measures velocity by converting kinetic energy into
pressure energy and displacing fluid in an attached manometer (simple pitot tube)
can combine pitot tube with second tube that has a hole perpendicular to flow
which allows static pressure to be measured at the other side of the manometer.
the change of height in the fluid of the manometer represents dynamic pressure
only
why does a fluid appear to flow against a pressure gradient - ANSWERS the
openings in the pipe only show static pressure. If a pitot tube is added it measures
static pressure and dynamic pressure and balances out the pressures so the fluid
is flowing down a pressure gradient. The constricted section of a pipe has higher
dynamic pressure due to it flowing at a higher velocity (Pdyn = 1/2pv^2)
how do birds use pitot tubes - ANSWERS they have a static port and
stagnation point directly facing fluid flow. Their nostril pitot tubes sense dynamic
pressure only and therefore different airspeeds which allows them to dynamically
soar using wind speed above the waves.
laminar vs turbulent flow - ANSWERS laminar
- reversible and reproducible
, - ordered
- even velocity gradient
- no mixing
turbulent
- irreversible and non-reproducible
- disordered
- efficient mixing
- erratic flow streams
reynolds number - ANSWERS the tendency of a fluid to flow in a laminar or
turbulent manner depending on viscous force (laminar) and inertial force
(turbulent), ratio of inertial force to friction force
viscous forces - ANSWERS due to fluid shearing over object, fluid exerts a force
on the object due to its viscosity and the shearing in the velocity gradient (μvS/l)
tangential to the objects surface
inertial forces - ANSWERS due to fluid colliding with an object, exerts a force
proportional to density, velocity and surface area of object (1/2ρSv^2) normal to
the objects surface
shift Re to being more turbulent - ANSWERS increasing velocity, increasing
characteristic length, having fluid with a higher density
shift Re to being more laminar - ANSWERS increasing fluid viscosity
