TEST 8 REMEDIAL
Water at 20 deg C is pumped at constant rate of
9m3/hour from a large reservoir resting on the floor to
the open top of an experimental absorption tower. The
point of discharge is 5m above the floor, and the
friction losses in the 50-mm pipe from the reservoir to
the tower amount to 2.5 J/kg. At what height in the
reservoir must the water level be kept if the pump can
only deliver 0.1 kW?
2. Calculate the Reynolds number if a liquid of viscosity
0.5 Ns/m2 and relative density of 500 Kg/m3 through
a 10 mm pipe flows with a Velocity of 3 m/s.
3. A cylinder with the height of 100 am filled with water.
A hole is located at 10 am above the ground. What is
its velocity?
4. Calculate the change in the system’s internal energy
if 3000 J of heat is added to a system and a work of
2500 J is done by the system.
5. A
liquid
column
manometer
contains
water, the density of which
we will take as 997
kg/m3.The left side is
connected to a gas of
unknown pressure, and the
right side is open to the
atmosphere at sea level,
which we will take as 101.3 kPa. We can also take
gravity as 9.81 m/s2.
6. A heat engine receives 500kJ of heat from a source and
rejects 200kJ of it to a sink . What is its efficiency?
7. The resistance of a wire is 20 Ω. What will be new
resistance, if it is stretched uniformly 8 times its
original length?
8. A sample of Argon gas at 0 deg C and 1 atm occupies
56.2 liters. Determine the number of moles of argon .
9. Kathryn slapped Daniel and he will probably
remember that burning sensation for the rest of his life.
This slap caused the temperature of his face to rise by
1.8 deg C (ouch!).Assuming that Kathryn’s hand has a
mass of 1.2 kg and about 0.150 kg of the tissue on his
face and the hand is affected by the incident, estimate
the velocity of her hand just before the impact. The
specific heat of the tissue is 3.8 kJ/kg.C
10. A heat pump has a COP of 2.5 supplies energy to a
house at a rate of 60,000 kJ./hr. Determine the power
needed by the heat pump.
1.
1.26 m
Reynold
number=(Density*velocity*Diameter)/viscosity=30
3. 4.2 m/s
4. 500 Joules
5. 102. 298 kPa
6. 60%
7. 1280 Ohm
8. Moles=2.5087 moles
9. 41 m/s
10. 24,000 kJ/hour
1.
2.