Page 169 - Physics

Pressure

(v) A horizontal plate of area 0⋅036m 2 (a) 0.98 kPa.
is beneath the surface of coconut (b) 2.0 kPa.
oil with a density of approximately (c) 3.0 kPa.
930 kg/m . The force on the plate due (d) 1.06 kPa.
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to the pressure of the oil is 290 (viii) A manometre contains mercury
N. What is the depth of the plate of density 14 000 kg/m . The
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beneath the surface of the oil? manometre is connected to a gas
(a) 0.87 m. supply and the difference in the
(b) 1.13 m. height of the mercury levels is
(c) 8.7 m. 72 mm. The atmospheric pressure
(d) 9.1 m. is 100 kPa. The gravitational fi eld

(vi) Each tyre of a car has an area of strength g is 10 N/ kg.
100 cm in contact with the ground. To gas
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The car has a mass of 1600 kg. supply
The weight of the car is equally
distributed amongst the four tyres.
The gravitational fi eld strength g
is 10 N/kg. What is the pressure
exerted on the ground? 72 mm
(a) 4.0 N/cm 2 Mercury
(b) 16 N/cm 2
(c) 40 N/cm 2

(d) 160 N/cm 2
(vii) The depth of water in a bath varies Figure 7.43
from 20.0 cm at the shallow to What is the pressure of the gas supply?
30.0 cm at the end of the plug, as (a) 90 kPa
shown in Figure 7.42. (b) 99 kPa

Water (c) 110 kPa
Bath
20 cm (d) 200 kPa
30 cm
(ix) A barometre is an instrument used
Plug
to measure atmospheric pressure. In
Figure 7.42 one type of barometer, the height of a
What is the pressure of water acting liquid in a tube is measured. In which
on the plug? The density of water is diagram does the height h represent
1 000 kg/m . atmospheric pressure?
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Physics Form 1 Final.indd 163 16/10/2024 20:57