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A block of wood measuring 0.8m by 0.5m by 2m floats in water. 1.2m of the block is submerged.
(i) Determine the weight of the water displaced.
(ii) Find the force required to just make the block fully submerged.
Date posted:
May 25, 2019
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A glass capillary contains enclosed air by a thread of mercury 15cm long when the tube is horizontal, the length of the enclosed air column is 24cm as shown.
(i) What is the length of the enclosed air column when the tube is vertical with the open end uppermost if the atmospheric pressure is 750mmHg?
(ii) What is the length of the enclosed air column when the tube is vertical with the closed end upper most if the atmospheric pressure is 750mmHg.
(iii) Explain why the mercury does not run out when the tube is vertical with the closed end uppermost.
Date posted:
May 25, 2019
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The figure below shows an inclined plane, a trolley of mass 60kg being pulled up the slope by a force of 200N parallel to the slope. The trolley is moved from X to Y.
Determine the
(i) Work output of the system.
(ii) Work input of the system.
(iii) The frictional force between the wheels of the trolley and the inclined plane.
(iv) The efficiency of the system.
(v) The velocity ratio of the system.
Date posted:
May 25, 2019
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A uniform metal strip is 3.0cm wides 0.6cm thick and 100cm long. The density of the metal is 2.7g/cm3.
Determine the weight of the metal strip.
Date posted:
May 25, 2019
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The graph (curve) below show the variation of force against extension (cm) of two spiral springs of same material, same wire thickness length but of different diameters (one large and the other small). Identify which graph (A or B) represents which spring.
Date posted:
May 25, 2019
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When the flask is placed in iced water the level on water rose and then fell. Explain this observation.
Date posted:
May 25, 2019
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A 20kw immersion water heater is used to heat 5.0 x 10-3m3 of water from 23oC to 100oC. Given that 30% of heat is lost to the surroundings, determine the time used in heating the water.
Date posted:
May 25, 2019
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An aircraft 300m from the ground traveling horizontally at 400m/s releases a parcel. Calculate the horizontal distance covered by the parcel from the point of release.(Ignore air resistance).
Date posted:
May 25, 2019
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In an experiment a crystal of potassium permanganate was placed in water as shown below.
After sometime, it was observed that the water turned purple. Explain this observation.
Date posted:
May 25, 2019
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The figure below shows a capillary tube placed in a trough of mercury.
Give a reason why the level of mercury in a capillary is lower than in the beaker.
Date posted:
May 25, 2019
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The figure below shows a pith ball in a container.
State and explain what would happen if air is blown over the mouth of the container.
Date posted:
May 25, 2019
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Sketch a velocity – time graph for a body initially moving at a velocity u before a force F is applied to it for 5 seconds and there after the force F is withdrawn.
Date posted:
May 25, 2019
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A turntable of radius 16cm is rotating at 960 revolutions per minute. Determine the angular speed of the turntable.
Date posted:
May 25, 2019
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A bus that carries goods in the under seats carrier is more stable than one that carries goods in the carrier at the top. Explain why this is so.
Date posted:
May 25, 2019
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The figure below shows two identical containers A and B containing hot water and ice block.
State with reason which water cools faster assuming that the wire gauge absorbs negligible heat.
Date posted:
May 25, 2019
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The diagram below shows a section of a micrometer screw gauge.
a) State the smallest measurement that can be made by the measurement that can be made by the micrometer screw gauge.
b) The thimble of the micrometer screw gauge is rotated through 2 ½ revolutions in the clockwise direction in order to
measure the diameter of a marble. State the diameter of the marble.
Date posted:
May 25, 2019
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The figure below shows a wire wound on a metal rod. The windings just touch each other. If the total number of complete loops was found to be 25 and the distance covered by the windings on the rod is 0.6cm, find the radius of the wire giving your answer in standard form.
Date posted:
May 25, 2019
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Calculate the critical angle of a ray of light passing from glass to water, if their refractive indices are 2/3 and 4/3 respectively.
Date posted:
May 25, 2019
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Explain why large convex mirrors are placed at certain points in supermarket
Date posted:
May 25, 2019
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An object 2.5 m tall is at a point 8m from a pinhole camera. If the distance of the screen is 8.16m from the object, calculate the size of the image
Date posted:
May 25, 2019
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The figure below shows a simple generator and the arrows indicate the direction of induced current.
(i) What type of generator is shown above ?
(ii) State two ways of increasing the brightness of the bulb.
(iii) If the bulb was replaced by a CRO sketch on the axes provided a graph to show the variation of output emf with position of the coil starting from vertical position.
Date posted:
May 25, 2019
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Calculate the photon energy in ultraviolet radiation whose frequency is 8.60 x 1014 Hz. (Plank’s constant h=6.63 x 10-34 Js)
Date posted:
May 25, 2019
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In an experiment to find the relationship between frequency of radiation and kinetic energy of photoelectrons in a photoelectric device, the following graph was obtained.
Use the graph to answer the following questions,
i) Determine the threshold frequency.
ii) Find the plank's constant h. .(Take the charge of an electron to be 1.6 x 10-19 C)
iii) Calculate the work function of the metal in joules.
Date posted:
May 25, 2019
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A wire of resistance 27 ohms is cut into three equal lengths. If the three wires are connected in parallel, what is the effective resistance?
Date posted:
May 25, 2019
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The initial mass of a radioactive substance is 40g. The substance has a half-life of 10 years. Determine the mass remaining after 40 years.
Date posted:
May 25, 2019
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Sketch the magnetic field pattern of the following arrangement.
Date posted:
May 25, 2019
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A sharp point of a pin is held over a positively charged electroscope. State and explain the observation made on the electroscope.
Date posted:
May 25, 2019
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The figure below shows a ray of light incident on a glass prism.
Given that the critical angle for the glass is 390, sketch on the diagram the path of the ray through the prism.
Date posted:
May 25, 2019
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State why parabolic reflectors are used in car headlights.
Date posted:
May 22, 2019
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The figure below shows the path of a ray of light through a glass prism. The speed of yellow
light in the prism is 1.88 × 108m/s.
(i) Determine the refractive index of the prism material for the light (speed of light in vacuum, c
= 3.0 × 108m/s.
(ii) Show on the figure, the critical angle, c, and determine its value.
(iii) Given that r = 21.2º, determine the angle θ.
Date posted:
May 22, 2019