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1. Rubber sucker– this is a shallow rubber cap. Before use it is moistened to get a good
seal then pressed firmly on a smooth surface so that the air inside is pushed out. The
atmospheric pressure will then hold it firmly
against the surface as shown below. They are used by
printing machines to lift papers, lifting glass panes,
2. Drinking straw– when a liquid is drawn using a straw air is sucked through the straw
to the lungs. This leaves the space in the straw partially evacuated. The atmospheric
pressure pushing down the liquid in the container becomes greater than the
pressure inside the straw and this forces the liquid into your mouth.
3. The syringe– they work in the principle as the straw. They are used by the doctors in
hospitals for giving injections.
4. Bicycle pump– it uses two valves, one in the pump (greasy leather) and the other in
the tire. When the handle is pushed in, the pressure inside the barrel becomes
greater than the one in the tire and this pushes air inside. The valve in the tire is
made such that air is locked inside once pumped.avy metal sheets
5. The siphon– it is used to empty tanks which may not be easy to empty by pouring
their contents out. The tubing must be lowered below the base of the tank. The
liquid flows out due to pressure difference caused by the difference in height (h ? g).
Moraa orina answered the question on April 4, 2018 at 18:03
- The height of the mercury column in a barometer is found to be 67.0 cm at a certain place.
What would be the height of...(Solved)
The height of the mercury column in a barometer is found to be 67.0 cm at a certain place.
What would be the height of a water barometer at the same place? (densities of mercury-
1.36 × 104
kg/m3
and water- 1.0 × 103
kg/m3
).
Date posted: April 4, 2018. Answers (1)
- The density of mercury is 13,600 kgm-3
. Determine the liquid pressure at a point 76 cm
below the surface of mercury. (Take g = 10...(Solved)
The density of mercury is 13,600 kgm-3
. Determine the liquid pressure at a point 76 cm
below the surface of mercury. (Take g = 10 Nkg-1
)
S
Date posted: April 4, 2018. Answers (1)
- A diver is 10 m below the surface of water in a dam. If the density of water is 1,000 kgm-3
, determine the pressure due...(Solved)
A diver is 10 m below the surface of water in a dam. If the density of water is 1,000 kgm-3
, determine the pressure due to the water on the diver. (Take g = 10 Nkg-1
)
Date posted: April 4, 2018. Answers (1)
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the floor is 420 cm2
,...(Solved)
A man of mass 84 kg stands upright on a floor. If the area of contact of his shoes and
the floor is 420 cm2
, determine the average pressure he exerts on the floor. (Take g =
10 N/Kg)
Date posted: April 4, 2018. Answers (1)
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Date posted: April 3, 2018. Answers (1)
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Date posted: April 3, 2018. Answers (1)
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An astronaut weighs 900 N on earth. On the moon he weighs 150 N. Calculate the moons’
gravitational strength. (Take g = 10 N/kg)(Solved)
An astronaut weighs 900 N on earth. On the moon he weighs 150 N. Calculate the moons’
gravitational strength. (Take g = 10 N/kg)
Date posted: April 3, 2018. Answers (1)
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What is induction?
What is earthing?
Date posted: April 3, 2018. Answers (1)
- 100 cm3
of fresh water of density 1,000 kgm-3
is mixed with 100 cm3
of sea water of density
1030 kgm-3
. Calculate the density of the mixture(Solved)
100 cm3
of fresh water of density 1,000 kgm-3
is mixed with 100 cm3
of sea water of density
1030 kgm-3
. Calculate the density of the mixture
Date posted: April 3, 2018. Answers (1)
- The mass of an empty density bottle is 20 g. Its mass when filled with water is 40.0 g and
50.0 g when filled with...(Solved)
The mass of an empty density bottle is 20 g. Its mass when filled with water is 40.0 g and
50.0 g when filled with liquid X. Calculate the density of liquid X if the density of water is
1,000 kgm-3
.
Date posted: April 3, 2018. Answers (1)
- The relative density of some type of wood is 0.8. Find the density of the wood in kg/m3(Solved)
The relative density of some type of wood is 0.8. Find the density of the wood in kg/m3
Date posted: April 3, 2018. Answers (1)
- The density of concentrated sulphuric acid is 1.8 g/cm3
. Calculate the volume of 3.1
kg of the acid.(Solved)
The density of concentrated sulphuric acid is 1.8 g/cm3
. Calculate the volume of 3.1
kg of the acid.
Date posted: April 3, 2018. Answers (1)
- A block of glass of mass 187.5 g is 5.0 cm long, 2.0 cm thick and 7.5 cm high.
Calculate the density of the glass...(Solved)
A block of glass of mass 187.5 g is 5.0 cm long, 2.0 cm thick and 7.5 cm high.
Calculate the density of the glass in kgm-3
.
Date posted: April 3, 2018. Answers (1)
- State the basic safety laboratory rules(Solved)
State the basic safety laboratory rules
Date posted: April 3, 2018. Answers (1)
- Example
100 cm3
of fresh water of density 1,000 kgm-3
is mixed with 100 cm3
of sea water of density
1030 kgm-3
. Calculate the density of the mixture.(Solved)
Example
100 cm3
of fresh water of density 1,000 kgm-3
is mixed with 100 cm3
of sea water of density
1030 kgm-3
. Calculate the density of the mixture.
Date posted: April 3, 2018. Answers (1)
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Explain why lightning is seen when there is thunderstorm.
Date posted: April 2, 2018. Answers (1)
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Date posted: April 1, 2018. Answers (1)
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Differentiate between temperature and heat.
Date posted: March 27, 2018. Answers (1)
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Date posted: March 26, 2018. Answers (1)
- A vibrator generates 120 waves in 5 seconds.The distance between successive crests of the waves is 8cm. Determine the time taken by the waves to...(Solved)
A vibrator generates 120 waves in 5 seconds.The distance between successive crests of the waves is 8cm. Determine the time taken by the waves to travel a distance of 150m.
Date posted: March 25, 2018. Answers (1)