Problem Sheet – Static Pressure
Shane Murray
Dept. of The Built Environment,
Institute of Technology, Carlow
1. What is the volume of an irregularly shaped solid of density 2310kg/m3 and
mass 1.32kg? http://screenr.com/Glp
2. Find the pressure at the bottom of a mercury column 760mm high. Express
your answer in kPa, bar & millibar.
http://screenr.com/Dlp
3. What pressure is caused by a head of water 50m high? Write your answer in
bar. http://screenr.com/Llp
4. Find the respective heights of water that exert the same pressure as (i) 15cm of
paraffin oil of relative density 0.8 & (ii) 30cm of olive oil of relative density
0.92.
http://screenr.com/6lp
5. Calculate the gauge pressure at a depth of 10m in sea-water of density
1030kg/m3
http://screenr.com/olp
6. What height of water barometer is equivalent to a 760mm mercury barometer
http://screenr.com/alp
7. A tank contains water to a depth of 1.5m. The barometric reading is 747mm of
mercury. Find the gauge & absolute pressures at the bottom of the tank.
http://screenr.com/ylp
8. Find the gauge & absolute pressures at the bottom of a tall vertical tub
containing 75cm of water, with 75cm of oil above the water, when the top is
open to the atmosphere, the barometric reading being 750mm of mercury &
the relative density of the oil being 0.8.
http://screenr.com/NDp
9. The pressure of water in a pipe on the ground floor of a building 800kPa,
while the pressure in the pipe on the top floor is 300kPa. What is the height of
the building?
http://screenr.com/2Dp
10. In a hydraulic jack a force F is applied to the small piston to lift the load on a
large piston. If the diameter of the small piston is 15mm and that of the large
piston is 189mm, calculate the value of F required to lift 1000kg. Find the
work done by F over a distance of 1m. If this work is done in 10s, find the
power input. Also find the distance moved by the load.
http://screenr.com/xDp & http://screenr.com/mDp
11. Two cylinders with pistons are connected by a pipe containing water. Their
diameter are 75mm & 600mm. What force on the smaller piston is required to
maintain a load of 3500kg on the larger piston? If the smaller piston has an
instantaneous speed of 0.5m/s, find the power input. Also find the speed of the
larger piston. http://screenr.com/ODp & http://screenr.com/rDp
12. An hydraulic testing machine is actuated by a hand-operated pump. The hand
lever has a ratio of 10 to 1 & is connected to a plunder of diameter 19mm. The
piston operating the testing head is 300mm in diameter. Calculate the intensity
of pressure in the oil & the force which must be applied to the lever when the
machine exerts a force of 210kN.
http://screenr.com/YDp &
http://screenr.com/JDp
13. An hydraulic press has a ram of 125mm diameter & a plunger if 12.5mm
diameter. What force is required on the plunger to raise a mass of 100kg on
the ram? If the plunger has a stroke of 250mm, how many strokes are
necessary to lift the weight 1m? Neglecting losses & assuming that the weight
moves continuously, what power is required to drive the plunger if the weight
is lifted in 12 minutes?
14. The pressure in a water pipeline is 2.4bar.Express this pressure as a head of
water
http://screenr.com/VDp
15. The liquid in a piezometer stands 1.5m above a point A in a pipeline. What is
the pressure at A in N/m2, if the liquid is (a) water & (b) oil of specific gravity
0.85. What is the head in metres of each liquid? http://screenr.com/ILp
16. In Fig 1, fluid A is oil (s=0.8), fluid B is brine (s=1.25). If a = 2.5m & h =
0.3m, what are
(a) the pressure &
(b) the static head at X?
http://screenr.com/Tqp & http://screenr.com/Hqp
X
a
h
Fluid A
Fluid B
Figure 1
17. (a) In Fig 1, Fluid A is water & Fluid B is mercury. What is the difference in
level h if the pressure at X is 140kN/m2 & a =1.5m?
(b) In Fig 1, Fluid A is gas, fluid B is water & h = 150mm. What is the
pressure in N/m2 at X? http://screenr.com/Nqp & http://screenr.com/2qp
18. Assuming that the atmospheric pressure is 101.3kN/m2, fins the absolute
pressure at X in Fig. 2 when fluid A is oil (s=0.82), fluid B is brine (s=1.1), a
= 20cm & h=55cm http://screenr.com/1qp & http://screenr.com/gqp
X
a
h
Fluid A
Fluid B
Figure 2
19. Assuming that the atmospheric pressure is equivalent to 768mm mercury, find
the absolute pressure at X in Fig 2, when fluid A is air, fluid B is water & h =
0.4m
http://screenr.com/Dqp & http://screenr.com/vqp
20. Fig. 3 shows a manometer being used to determine a flow rate from the
pressure drop across an orifice plate. If fluid A is water, fluid B is mercury &
the manometer height is 240mm, find þ1 – þ2 in kPa. Express this result as a
loss of head. http://screenr.com/pTR & http://screenr.com/RTR
1
2
Fluid A
h
Fluid B
Figure 3