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In an experiment to determine the specific latent heat of vaporization of water, steam at 100ºC was passed into water contained in a well-lagged copper...
(Solved)
In an experiment to determine the specific latent heat of vaporization of water, steam at 100ºC was passed into water contained in a well-lagged copper calorimeter. The following measurements were made:
- Mass of calorimeter = 55g
- Initial mass of water = 75g
- Final mass of calorimeter + water + condensed steam = 133g
- Final temperature of the mixture = 30ºC
[Specific heat capacity of water = 4200JKgˉ¹kˉ¹ and specific heat capacity of copper= 390JKgˉ¹kˉ¹]
(i) mass of condensed steam.
heat gained by the calorimeter and water if the initial temperature of the
calorimeter + water = 20ºC.
(ii) given that L is the specific latent heat of vaporization of steam,
(I) Write an expression for the heat given out by steam.
(II) Determine the value of L.
Date posted:
September 26, 2019
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Answers (1)
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The figure below shows an inclined plane, a trolley of mass 30kg is pulled up a slope by a force of 100N, parallel to the...
(Solved)
The figure below shows an inclined plane, a trolley of mass 30kg is pulled up a slope by a force of 100N, parallel to the slope. The trolley moves so that the centre of mass C travels from points A to B.

(i) What is the work done on the trolley against the gravitational force in moving from A to B.?
(ii) Determine the work done by the force in moving the trolley from A to B.
(iii) Determine the efficiency of the system.
(iv) Determine the work done in overcoming the frictional force.
(v) Determine the mechanical advantage of the system.
Date posted:
September 26, 2019
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Answers (1)
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In an experiment to determine the density of a liquid, the following readings were made.
Mass of empty density bottle = 20g
Mass of bottle filled with...
(Solved)
In an experiment to determine the density of a liquid, the following readings were made.
Mass of empty density bottle = 20g
Mass of bottle filled with water = 70g
Mass of bottle filled with a liquid = 695g
a. Find the density of the liquid, given that density of water is 1000kgmˉ³.
b. Find the mass of the liquid.
Date posted:
September 26, 2019
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Answers (1)
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Sketch a graph of displacement against time for a transverse wave of frequency of 50Hz of at least two cycles with amplitude 2cm.
(Solved)
Sketch a graph of displacement against time for a transverse wave of frequency of 50Hz of at least two cycles with amplitude 2cm.
Date posted:
September 26, 2019
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Answers (1)
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The diagram below shows a metal tube made of iron and copper. The joint is tight at room temperature.
(Solved)
The diagram below shows a metal tube made of iron and copper. The joint is tight at room temperature.

Explain how you would separate the two by changing the temperature given that copper expands more than iron for some change in temperature.
Date posted:
September 26, 2019
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Answers (1)
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A student used the measuring instrument shown below to measure the thickness of a cylindrical wire, If the wire is 10cm long, find the volume...
(Solved)
A student used the measuring instrument shown below to measure the thickness of a cylindrical wire, If the wire is 10cm long, find the volume of the wire.

Date posted:
September 26, 2019
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Answers (1)
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A lorry weighing 6400kg is lifted with a jack screw of 11mm pitch. If the handle is 28cm from the screw
(Solved)
A lorry weighing 6400kg is lifted with a jack screw of 11mm pitch. If the handle is 28cm from the screw
(i) Find the velocity ratio
(ii) Neglecting the frictional force, Calculate mechanical advantage, MA)
(iii) Determine the force applied
Date posted:
September 26, 2019
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Answers (1)
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Sometimes work is not done even if there is an applied force. Give a reason
(Solved)
Sometimes work is not done even if there is an applied force. Give a reason
Date posted:
September 26, 2019
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Answers (1)
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A stone of mass 40g is tied to the end of a string 50cm long and whirled in a vertical circle of 2 revolutions per...
(Solved)
A stone of mass 40g is tied to the end of a string 50cm long and whirled in a vertical circle of 2 revolutions per second. Calculate the maximum tension in the string
Date posted:
September 26, 2019
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Answers (1)
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A particle moving along a circular path of radius 3.0cm describes an arc of length 2cm every second. Determine
(Solved)
A particle moving along a circular path of radius 3.0cm describes an arc of length 2cm every second. Determine
I. Its angular velocity, W
II. Its periodic time, T
Date posted:
September 26, 2019
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Answers (1)
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The figure below shows a body being pulled by a constant force of 10N for a distance of 4m over wooden surface. The co-efficient of...
(Solved)
The figure below shows a body being pulled by a constant force of 10N for a distance of 4m over wooden surface. The co-efficient of friction is 0.03

Find the
(i) Acceleration of the body
(ii) Velocity of the body after the 4 metres
(iii) Kinetic energy of the body after the 4 metres
Date posted:
September 26, 2019
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Answers (1)
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a).In an experiment to estimate the diameter of an oil molecule, an oil drop of diameter 0.06cm spread over a circular patch whose diameter is...
(Solved)
a).In an experiment to estimate the diameter of an oil molecule, an oil drop of diameter 0.06cm spread over a circular patch whose diameter is 20cm. Determine
(i) The volume of the oil drop
(ii) The area of the patch covered by oil
(iii) The diameter of the oil molecule
(b) State any one assumption made in a (iii) above
Date posted:
September 26, 2019
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Answers (1)
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An x-ray tube operating at a potential difference of 50KV has a tube current 20mA.Calculate.
(Solved)
An x-ray tube operating at a potential difference of 50KV has a tube current 20mA.Calculate.
i) The electric power input.
ii) The number of electrons hitting the target per second given that e = 1.6 x 10-19.
iii) The velocity of electrons when they hit the target.
Date posted:
September 26, 2019
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Answers (1)
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Calculate the maximum velocity of electrons that would produce x-rays of frequency 8.0x108HZ if only 20% of kinetic energy is converted to x – rays.(Take...
(Solved)
Calculate the maximum velocity of electrons that would produce x-rays of frequency 8.0x108HZ if only 20% of kinetic energy is converted to x – rays.(Take planks constant = 6.63 x 10-34 JS and mass of electron = 9.1 x 10-31 kg).
Date posted:
September 26, 2019
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Answers (1)
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The diagram below shows a glass prism and incident ray striking the surface XY.
(Solved)
The diagram below shows a glass prism and incident ray striking the surface XY.

i) Indicate on the diagram the path of the emergent ray.
ii) Calculate the refractive index of the glass prism given that the critical angle of glass is 420
Date posted:
September 26, 2019
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Answers (1)
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Give a reason why it is not advisable to take shelter under a tree especially when it is raining.
(Solved)
Give a reason why it is not advisable to take shelter under a tree especially when it is raining.
Date posted:
September 26, 2019
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Answers (1)
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Give a reason why a candle flame is blown away when a highly charged rod is brought close to it.
(Solved)
Give a reason why a candle flame is blown away when a highly charged rod is brought close to it.
Date posted:
September 26, 2019
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Answers (1)
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In the circuit diagram in figure below, the voltmeter reads 4 volts.
(Solved)
In the circuit diagram in figure below, the voltmeter reads 4 volts.

Determine the ammeter reading.
Date posted:
September 26, 2019
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Answers (1)
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The figure below shows an object O placed in front of a plane mirror.
(Solved)
The figure below shows an object O placed in front of a plane mirror.

Use a ray diagram to locate the position of the image.
Date posted:
September 26, 2019
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Answers (1)
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An automobile of mass 500 kilograms is accelerated from rest a long a horizontal surface. The force produced by the engine is 300N and that...
(Solved)
An automobile of mass 500 kilograms is accelerated from rest a long a horizontal surface. The force produced by the engine is 300N and that due to friction is 50N.What is the accelerating force and what is the acceleration produced.
Date posted:
September 26, 2019
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Answers (1)