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A man has 2m³ of concrete delivered to his home and he needed to carry it down in a wheelbarrow. If each barrow load weighs...
(Solved)
A man has 2m³ of concrete delivered to his home and he needed to carry it down in a wheelbarrow. If each barrow load weighs 2500N, how many trips will he have to make?
(Density of concrete = 3000kgm-3).
Date posted:
May 30, 2019
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Answers (1)
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The figure below shows a ray of white light dispersed in a triangular prism. The speed of violet light in the prism in 1.88 ×...
(Solved)
The figure below shows a ray of white light dispersed in a triangular prism. The speed of violet light in the prism in 1.88 × 108m/s.
a) Explain how glass disperses white light into red and violet bands.
b) Determine the refractive index of the prism material for light (take speed of light in vacuum = 3×108m/s
c) Show on the figure the critical angle C for violet light and determine its value.
d) Given that r =21.5° determine the angle
e) On the same figure, sketch the part of red light after white light strikes the prism if the prism was replaced by another of
similar shape but lower refractive index. (Use a dotted line for the answer)
Date posted:
May 30, 2019
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Answers (1)
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Figure below shows a simple barometer.
a) What is the region A?
b) What keeps the mercury in the tube?
c) What is the value of the...
(Solved)
Figure below shows a simple barometer.
a) What is the region A?
b) What keeps the mercury in the tube?
c) What is the value of the atmospheric pressure being shown by the barometer?
d) What would happen to the reading if the barometer were taken up a high mountain.
e) Give a reason for (d) above.
Date posted:
May 30, 2019
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Answers (1)
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The diagram below shows a section of a micrometer screw gauge.
The thimble of the micrometer screw gauge is rotated through two and half revolutions in...
(Solved)
The diagram below shows a section of a micrometer screw gauge.
The thimble of the micrometer screw gauge is rotated through two and half revolutions in the clockwise direction in order to measure the diameter of a marble. State the diameter of the marble if the instrument had a negative error of
0.03mm.
Date posted:
May 30, 2019
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Answers (1)
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The primary coil of a transformer has 1200 turns and the secondary coil has 60 turns. The transformer is connected to a 240 V a.c source. (i) The output...
(Solved)
The primary coil of a transformer has 1200 turns and the secondary coil has 60 turns. The transformer is connected to a 240V a.c source.
i) The output voltage.
ii) The output current when the primary coil has a current of 0.5A (Assume there is no energy losses)
iii) One of the primary ways in which power is lost in transformers is through eddy currents. State how eddy currents can be
minimized.
Date posted:
May 30, 2019
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Answers (1)
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In an experiment to determine the speed of sound, an observer stood in front of a high wall at a distance of 80m. He
clapped two...
(Solved)
In an experiment to determine the speed of sound, an observer stood in front of a high wall at a distance of 80m. He
clapped two boards together at such a rate that each clap coincided with the echo from the wall. A second observer noted
a time of 9.5 seconds starting with first clap and ending with the 21st clap.
i) Calculate the speed of sound under these conditions.
ii) Describe one probable source of error in this experiment.
iii) State one way in which sound wave differ from light waves.
Date posted:
May 30, 2019
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Answers (1)
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A person standing behind a wall hears a bell ringing although he cannot see the bell. What property of sound enables him
to hear the sound?
(Solved)
A person standing behind a wall hears a bell ringing although he cannot see the bell. What property of sound enables him
to hear the sound?
Date posted:
May 30, 2019
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Answers (1)
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Explain why it is not advisable to use a 10A fuse for a hair dryer rated 2.5Kw, 240V.
(Solved)
Explain why it is not advisable to use a 10A fuse for a hair drier rated 2.5Kw, 240V.
Date posted:
May 30, 2019
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Answers (1)
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Explain why the cathode of a CRO is coated with oxides of metals such as Barium and Strontium.
(Solved)
Explain why the cathode of a CRO is coated with oxides of metals such as Barium and Strontium.
Date posted:
May 30, 2019
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Answers (1)
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A box of mass 500g has dimension 10m × 5m × 3m. Determine the maximum pressure exerted by the box on a flat surface. (Take...
(Solved)
A box of mass 500g has dimension 10m × 5m × 3m. Determine the maximum pressure exerted by the box on a flat surface. (Take g = 10N/kg)
Date posted:
May 30, 2019
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Answers (1)
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The figure below represents a hydraulic brake.
A force of 20N is applied on the foot pedal connected to a piston of area 0.0005m² and this...
(Solved)
The figure below represents a hydraulic brake.
A force of 20N is applied on the foot pedal connected to a piston of area 0.0005m² and this causes a stopping force of 5000N. Calculate
i) The pressure in the master cylinder.
ii) The area of the slave piston.
iii) The velocity ratio
Date posted:
May 30, 2019
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Answers (1)
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A block of glass of mass 0.25kg floats in mercury of density 1.36 × 104kg/m³. What volume of the glass lies under the surface of...
(Solved)
A block of glass of mass 0.25kg floats in mercury of density 1.36 × 104kg/m³. What volume of the glass lies under the surface of mercury?
Date posted:
May 30, 2019
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Answers (1)
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A rectangular block of cross-sectional area 0.08m² is immersed in a liquid of density 1200kg/m³. The top and the lower
surfaces are 80cm and 200cm below...
(Solved)
A rectangular block of cross-sectional area 0.08m² is immersed in a liquid of density 1200kg/m³. The top and the lower
surfaces are 80cm and 200cm below the surface of the liquid respectively.
i) What is the downward force on the top of the block?
ii) Calculate the upthrust on the block.
Date posted:
May 30, 2019
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Answers (1)
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Explain why it is necessary to add a little flour to the water when boiling it to cook ugali.
(Solved)
Explain why it is necessary to add a little flour to the water when boiling it to cook ugali.
Date posted:
May 30, 2019
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Answers (1)
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A uniform rod of length 4m and mass of 4kg is pivoted at 3.6m mark. The rod is held horizontal with a vertical rope at...
(Solved)
A uniform rod of length 4m and mass of 4kg is pivoted at 3.6m mark. The rod is held horizontal with a vertical rope at the 4m
mark, as shown in the figure 3.0 below.
Calculate the tension, T in the rope (Take g = 10N/kg)
Date posted:
May 30, 2019
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Answers (1)
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A Spring extends by 0.7cm when a mass of 420g is hang on it on earth. By what length would the spring extend if the...
(Solved)
A Spring extends by 0.7cm when a mass of 420g is hang on it on earth. By what length would the spring extend if the same
set up was taken to the moon where the gravitational intensity is one-sixth of that one earth.Take gravitational field intensity on surface of Earth g, 10N/kg.
Date posted:
May 30, 2019
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Answers (1)
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The figure below shows a plane mirror and the word PHYSICS written on its front.
On the same diagram, write down the appearance of the word...
(Solved)
The figure below shows a plane mirror and the word PHYSICS written on its front.
On the same diagram, write down the appearance of the word after reflection on the mirror.
Date posted:
May 30, 2019
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Answers (1)
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Sketch the graph of density of water against temperature upto 10oC.
(Solved)
Sketch the graph of density of water against temperature upto 10oC.
Date posted:
May 30, 2019
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Answers (1)
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State one similarity between “moment of force about a point” and “work done”
(Solved)
State one similarity between “moment of force about a point” and “work done”
Date posted:
May 30, 2019
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Answers (1)
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The figure below shows a burette containing a liquid up to the level marked on the figure. 20 drops of the liquid are now run...
(Solved)
The figure below shows a burette containing a liquid up to the level marked on the figure. 20 drops of the liquid are now run out of the burette. If each drop has a volume of 1.1ml. Mark on the figure the new level of the liquid in the burette.
Date posted:
May 30, 2019
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Answers (1)