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A body weighs 40N in air, 30N in water and 35N when in liquid X. Find the relative density of liquid X
(Solved)
A body weighs 40N in air, 30N in water and 35N when in liquid X. Find the relative density of liquid X
Date posted:
May 31, 2019
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Answers (1)
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Two liquids of density 1100kg/m3 and 850kg/m3 are mixed in equal volumes. The mixture fills a tank of 300cmx 40cm x 50cm to the bring...
(Solved)
Two liquids of density 1100kg/m3 and 850kg/m3 are mixed in equal volumes. The mixture fills a tank of 300cmx 40cm x 50cm to the bring calculate the mass of each liquid
Date posted:
May 31, 2019
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Answers (1)
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A crane just lifts 9940N when an effort of 116N is applied. Find its velocity ratio if the crane has an efficiency of 72%
(Solved)
A crane just lifts 9940N when an effort of 116N is applied. Find its velocity ratio if the crane has an efficiency of 72%
Date posted:
May 31, 2019
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Answers (1)
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A Power station has an input of 30kw at a potential difference of 5kv.A transformer with a secondary coil of 1000 turns is used to...
(Solved)
A Power station has an input of 30kw at a potential difference of 5kv.A transformer with a secondary coil of 1000 turns is used to step down the voltage to 1000v for transmission along a grid .Assuming there are no power loses in the transformer .calculate.
i) current in the primary coil
ii) The number of turns in the primary coil
iii) The current in the secondary coil
iv) State which of the coils is thick and why
Date posted:
May 31, 2019
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Answers (1)
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Show the charge distribution on the hollow conductor shown below if it is positively charged.
(Solved)
Show the charge distribution on the hollow conductor shown below if it is positively charged.

Date posted:
May 31, 2019
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Answers (1)
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The figure below shows a simple electric motor. Study the figure and answer the questions that follow.
i) Indicate on the diagram the direction of rotation...
(Solved)
The figure below shows a simple electric motor. Study the figure and answer the questions that follow.

i) Indicate on the diagram the direction of rotation of the coil.
ii) Explain how the motor works specifying clearly the functions of the parts P and Q.
iii) State one way by which the speed of this motor can be increased.
Date posted:
May 31, 2019
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Answers (1)
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The figure shows a loudspeaker producing sound waves in air.
i) Explain how compression and rarefactions are formed.
iii) The wavelength of the waves produced is...
(Solved)
The figure shows a loudspeaker producing sound waves in air.

i) Explain how compression and rarefactions are formed.
iii) The wavelength of the waves produced is 0.4m. Determine the frequency of the waves if the speed of sound in air is 330m/s.
Date posted:
May 31, 2019
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Answers (1)
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The figure below shows a ray of light incident on a plane mirror.The mirror is rotated through 10° clockwise about point O in an axis...
(Solved)
The figure below shows a ray of light incident on a plane mirror.

The mirror is rotated through 10° clockwise about point O in an axis perpendicular to plane mirror. Determine the angle between the incident ray and the new reflected ray.
Date posted:
May 31, 2019
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Answers (1)
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Describe the changes that can be observed during discharging process of a lead –acid accumulator
(Solved)
Describe the changes that can be observed during discharging process of a lead –acid accumulator
Date posted:
May 31, 2019
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Answers (1)
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Calculate the maximum speed at which the car can go round the bend without skidding if the coefficient of friction between the tyres and the...
(Solved)
Calculate the maximum speed at which the car can go round the bend without skidding if the coefficient of friction between the tyres and the ground is 0.5.
Date posted:
May 31, 2019
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Answers (1)
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A 50W heating coil is totally immersed in 100g of water contained in an insulated flask of negligible heat capacity. The initial temperature of water...
(Solved)
A 50W heating coil is totally immersed in 100g of water contained in an insulated flask of negligible heat capacity. The initial temperature of water in the flask is 20oc.
i) Determine how long it takes for the water to boil at 100oC when the heater is switched on
ii) After the water has been boiling for 15 minutes, it is found that the mass of water in the flask has decreased to 80g. Assuming no external heat losses, calculate a value for the specific latent heat of vaporization of water
Date posted:
May 31, 2019
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Answers (1)
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A hole of area 2.0cm2 at the bottom of a tank 5m deep is closed with a cork. Determine the force on the cork when...
(Solved)
A hole of area 2.0cm2 at the bottom of a tank 5m deep is closed with a cork. Determine the force on the cork when the tank is filled with sea water of density 1.2g/cm3.
Date posted:
May 31, 2019
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Answers (1)
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An electric kettle with a 2.0kw heating element has a heat capacity of 400j/k. 1.0kg of water at 20°C is placed in the kettle. The...
(Solved)
An electric kettle with a 2.0kw heating element has a heat capacity of 400j/k. 1.0kg of water at 20°C is placed in the kettle. The kettle is switches on and it is found that 13 minutes later the mass of water in it is 0.5kg. Ignoring heat losses ; calculate
i) Total heat supplied.
ii) Heat used for the kettle.
iii) Heat used to raise temperature of 1kg of water from 20°C to 100°C.
iv) Heat to change water at 100°C to steam at 100°C.
v) The specific latent heat of vaporization of water.
Date posted:
May 31, 2019
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Answers (1)
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A car of mass 800g is initially moving at 25m/s. Calculate the force needed to bring the car to rest over a distance of 20m.
(Solved)
A car of mass 800g is initially moving at 25m/s. Calculate the force needed to bring the car to rest over a distance of 20m.
Date posted:
May 31, 2019
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Answers (1)
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In an experiment to determine the thickness of an oil molecule, an oil drop of volume 3.60 x 10-6 m3 was observed to form a...
(Solved)
In an experiment to determine the thickness of an oil molecule, an oil drop of volume 3.60 x 10-6 m3 was observed to form a circular patch of diameter 0.016m on the surface of water covered with lycopodium powder
i). Explain why the oil drop forms a circular patch.
ii) Determine the thickness of the oil molecule
Date posted:
May 31, 2019
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Answers (1)
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The figure below shows a uniform plank AB of length 10m weighing 500N. Two masses measuring 25kg and 60kg are loaded on its ends.
Determine the...
(Solved)
The figure below shows a uniform plank AB of length 10m weighing 500N. Two masses measuring 25kg and 60kg are loaded on its ends.

Determine the distance from point A where a support should be placed for the plank to balance horizontally.
Date posted:
May 31, 2019
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Answers (1)
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A small drop of oil has a volume of 5 × 10-8m³. When it is put on the surface of some clean water, it forms...
(Solved)
A small drop of oil has a volume of 5 × 10-8m³. When it is put on the surface of some clean water, it forms a circular film of 0.1m² in area; what is the size the a molecule oil.
Date posted:
May 31, 2019
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Answers (1)
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The distance between the ice point and steam point on a liquid in glass thermometer is 30cm. what temperature is recorded when the mercury thread...
(Solved)
The distance between the ice point and steam point on a liquid in glass thermometer is 30cm. what temperature is recorded when the mercury thread is 12cm above the ice point?
Date posted:
May 31, 2019
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Answers (1)
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A single spring stretches by 2.0 cm when supporting a load of 50N. If in the system below the springs are identical and have negligible...
(Solved)
A single spring stretches by 2.0 cm when supporting a load of 50N. If in the system below the springs are identical and have negligible weight

Find:
a) The total extension of the system.
b) The total spring constant.
Date posted:
May 31, 2019
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Answers (1)
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The diagram below shows a micrometer screw gauge used by a student to measure the thickness of a wire. If it has a zero error...
(Solved)
The diagram below shows a micrometer screw gauge used by a student to measure the thickness of a wire. If it has a zero error of 0.06mm, what is the actual thickness of the wire?

Date posted:
May 31, 2019
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Answers (1)