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A car of mass 1200kg is negotiating a curve of radius 45m on a horizontal road. The force of friction between the tyres and the road is 6700N. Determine the maximum speed at which the car can be driven on the curve without going off the road.
Date posted:
June 3, 2019
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The diagram below shows a simplified hydraulic braking system of a car.
(i) State the property of the liquid (oil) that makes its more suitable than a gas for use as a brake fluid.
(ii) Explain how the system works starting from when the driver presses the foot pedal.
Date posted:
June 3, 2019
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Explain how a person is able to draw milk from a glass using a straw.
Date posted:
June 3, 2019
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The following figure shows a wheel and axle used to raise a load W by applying an effort F. The radius of the larger wheel is R and the small wheel is y.
Given that v = 5cm and R is 8cm, determine the effort required to raise a load of 20N if the efficiency of the system is 80%.
Date posted:
June 3, 2019
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An immersion heater takes 30 minutes to heat 20kg of water from 250C to 600C. How long would the same heater take to heat the same mass of kerosene through the same temperature range. (Assume no heat is lost to the surrounding).
Specific heat capacity of water = 4200JKgˉ¹Kˉ¹
Specific heat capacity of kerosene = 2200JKgˉ¹Kˉ¹
Date posted:
June 3, 2019
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A ball of mass 100g is dropped from a height of 1.25m above the ground surface.
It rebounds to a height of 1.1m. Calculate
(i) velocity of the ball before impact.
(ii) force of impact if the ball is in contact with the surface for 0.2S (g = 10N/kg).
Date posted:
June 3, 2019
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The figure below shows a set-up that can be used to verify Charles law of gases.
(i) State the measurements that should be taken in the experiment.
(ii) Explain how the measurements taken in (i) above can be used to verify Charles law.
Date posted:
June 3, 2019
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The figure below shows a uniform bar in equilibrium under the action of tin forces.
Determine the value of F.
Date posted:
June 3, 2019
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A metal bench feels colder than a wooden one when one sits on it on a cold morning even though both are at the same temperature. Explain this observation.
Date posted:
June 3, 2019
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The diagram below shows an empty wine glass.
(a) State the effect on its stability when wine is put into the glass.
(b) Explain your answer in (a) above.
Date posted:
June 3, 2019
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Complete figure (a) and (b) below by showing the level of the liquids in the glass tubes.
Date posted:
June 3, 2019
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The figure below shows a sheet of paper rolled into a tube.
When a stream of air at high speed is blown into the tube, the paper tube collapses.
Explain this observation.
Date posted:
June 3, 2019
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The figure below shows a wire A and a spring B made of the same material. The thickens of the wire is the same in both cases. Masses are added on each at the same interval and the extension noted each time. Sketch the graphs of load against extension for each assuming Hookes law is obeyed.
Date posted:
June 3, 2019
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The graph below shows stopping potential V against frequency for a photocell.
From the graph determine:
(i) Threshold frequency
(ii) Planck’s constant
(iii) Work function of the metal
(Takee = 1.6 x 10-19c)
Date posted:
June 3, 2019
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Complete the diagram below indicating the rays that will lead to the formation of the image I shown below and locate the object position.
Date posted:
June 3, 2019
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A student designed a transformer to provide power to an electric bell marked 24W, 6V from a 240V mains. He wound 50 turns and N turns on an iron ring. When he a connected the coil of 50 turns to the bell and the N turns coil to an a.c, he found that the transformer was only 60% efficient. Find:
(i) The value of N
(ii) The power in the coil with N turns
Date posted:
June 3, 2019
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Use the law to determine the direction of the induced current in the circuit below
Date posted:
June 3, 2019
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The graph below shows the variation of potential difference V with current, I for a certain cell.
From the graph determine:
(i) Internal reaction of the cell.
(ii) The e.m.f of the cell
Date posted:
June 3, 2019
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The figure below shows an arrangement of capacitor connected to a 10V DC supply.
Determine
(i) The combined capacitance of the arrangement.
(ii) The total energy stored.
Date posted:
June 3, 2019
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In the pipe below complete the diagram to show how air in the open pipe vibrates with a frequency of first overtone.
Date posted:
June 3, 2019
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The figure below shows a set up by a student.
State and explain what happens to the sound from the buzzer as the bottle and its contents are cooled to 0oC
Date posted:
June 3, 2019
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The figure shows a simple cell.
Use the information on the figure to answer the questions below.
(a) Name the parts labeled A and B
(b) It is observed that the bulb goes off after a short time. Explain this observation
Date posted:
June 3, 2019
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A mine worker stands between two vertical cliffs 400m from the nearest cliff. The cliff are x and metres apart. Every time he strike the rock once , he hears two echoes, the first one after 2.5 seconds, while the second follows 2 seconds later.
Calculate
(i) The speed of sound in air.
(ii) The value of x
Date posted:
June 3, 2019
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A bullet of mass 20g moving at 400 m/s strikes a block of wood of mass 3.5kg initially at rest. The bullet sticks into the block and the two move off together on a horizontal surface, where a frictional retarting force of 4N is acting between the block and surface.
(i) Determine the initial common velocity of bullet and wooden block.
(ii) What distance does the block move before coming to rest?
Date posted:
June 3, 2019
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A striker kicks a ball of mass 250g initially at rest with a force of 75N. if the foot was in contact with the ball for 0.10sec. Calculate the take off velocity of the ball.
Date posted:
June 3, 2019
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1200g of a liquid at 100C is poured into a well-logged calorimeter. An electric heater rated 1KW is used to heat the liquid. The graph in fig 4 below shows the variation of temperature of the liquid with time.
Use the graph to answer the following questions:
(i) What is the boiling point of the liquid?
(ii) How much heat is given out by the heater to take the liquid to the boiling point?
(iii) Determine the specific heat capacity of the liquid stating any assumptions made.
(iv) If 50g of the liquid vapour was collected by the end of the 8th minute, determine the specific latent heat of vaporization of the liquid.
Date posted:
June 3, 2019
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A test tube of mass 10g and uniform cross-sectional area 4cm2 is partly filled with lead shots and floats vertically in water with 5cm of its length submerged.
Find the:-
(i) Mass of the lead shots.
(ii) Length of the test tube that would be submerged in a liquid of density 0.75g/cm3.
Date posted:
June 3, 2019
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The figure below shows a rectangular buoy of mass 4000kg tethered to the sea-bed by a wire. The dimensions are 4m x 1.5m x 2.2m.
Calculate the :-
(i) Weight of sea water displaced by the buoy (density of sea water = 1100kg/m3)
(ii) Upward force exerted on the buoy by the water.
(iii) Tension in the wire
Date posted:
June 3, 2019
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The effort piston of a hydraulic machine is of radius 2.8 cm, while that of the load piston is of radius 14cm. The machine raises a load of 120 kg at a constant velocity through 2.5m. If the machine has an efficiency of 80%, find:-
(i) the velocity ratio of the hydraulic machine.
(ii) The mechanical advantage of the hydraulic machine.
(iii) The effort needed to raise the load.
Date posted:
June 3, 2019
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A quantity of air occupied 500cm3 at 150C when the pressure was 76 cm. Hg. At what temperature would it occupy 43 if the pressure was 85cmHg?
Date posted:
June 3, 2019