sem 2 key definitions Flashcards
What is the first law of thermodynamics?
The change of internal energy of the open system, between its initial and final states of internal equilibrium (Q-W=U)
What does the term adiabatic mean?
a type of thermodynamic process that occurs without transferring heat or mass
What is an isothermal process?
a type of thermodynamic process in which temperature is constant
What is specific heat?
the amount of energy transferred to raise a unit mass (1kg) by one degree(K)
What is the energy equation for a closed system?
Q-W=E
What does a nozzle do?
A nozzle increases the velocity of the fluid but reduces its pressure
What does a diffuser do?
A diffuser increases the pressure of the fluid but reduces its velocity
What is an incompressible fluid?
a fluid with a constant density
What is gauge pressure?
gauge pressure is the pressure relative to the local atmospheric pressure
What is absolute pressure?
pressure relative to absolute zero
How would you calculate pressure at the bottom of a tank filled with water?
P(bottom)=P(atm/above)+pgh
What is the hydrostatic paradox?
different-shaped containers with the same base area, which are filled with a liquid of the same height, have the same applied force acting on their base
How would you overcome the limitations of siphoning to increase flowrate?
*use 2 siphons
*increase diameter of pipe
*decrease height of point 2
to reduce minium pressure then further lower pipe exit
What are non-siphoning solutions to increase flowrate?
using a pump or tapping to bottom of tank
What is happening when an object moves from a lower position to a higher position?
work acts on the surroundings, (for water; the water is pushed back to overcome surface tension
