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Three insoluble powders A, B and C of densities dA, dB and dC, such that dA>dB>dC, are mixed and put into a container.The container is...
(Solved)
Three insoluble powders A, B and C of densities dA, dB and dC, such that dA>dB>dC, are mixed and put into a container.The container is then whirled in a horizontal circle as shown in the figure below.
(i) Label on the figure, the positions of the powders after some time.
(ii) Give a reason for your answer in (i)
Date posted:
September 6, 2019
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Answers (1)
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A car decelerates uniformly from a velocity of 20m/s to rest in 4 seconds. It takes 4 seconds to reverse with uniform acceleration to its...
(Solved)
A car decelerates uniformly from a velocity of 20m/s to rest in 4 seconds. It takes 4 seconds to reverse with uniform acceleration to its original starting point.
(i) Sketch a velocity time graph for the motion of the car.
(ii) Use your sketch in c (i) to determine the total displacement of the car.
Date posted:
September 6, 2019
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Answers (1)
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The figure below shows the displacement – time graph of the motion of a particle.
State the nature of the motion of the particle between?
(i)...
(Solved)
The figure below shows the displacement – time graph of the motion of a particle.
State the nature of the motion of the particle between?
(i) AB
(ii) BC
(iii CD
Date posted:
September 6, 2019
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Answers (1)
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State the physical quantity represented by the gradient of a displacement – time graph
(Solved)
State the physical quantity represented by the gradient of a displacement – time graph
Date posted:
September 6, 2019
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Answers (1)
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A substance of mass 2kg and specific heat capacity 400J/kg/k initially at 800C is immersed in water at 190C. If the final temperature of the...
(Solved)
A substance of mass 2kg and specific heat capacity 400J/kg/k initially at 800C is immersed in water at 190C. If the final temperature of the mixture is 200C. Calculate the mass of water. (Specific heat capacity of water = 4200J/kg/k)
Date posted:
September 6, 2019
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Answers (1)
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A force of 20N is used to stretch a spring through 5cm. Calculate the elastic potential energy stored in the spring.
(Solved)
A force of 20N is used to stretch a spring through 5cm. Calculate the elastic potential energy stored in the spring.
Date posted:
September 6, 2019
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Answers (1)
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A pipe of radius 3mm is connected to another pipe of radius 9mm. If water flows in the water pipe at a speed of 2m/s,...
(Solved)
A pipe of radius 3mm is connected to another pipe of radius 9mm. If water flows in the water pipe at a speed of 2m/s, what is the speed in the narrower pipe?
Date posted:
September 6, 2019
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Answers (1)
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A uniform 120m metal rod is pivoted near one of its ends and kept in equilibrium by a spring balance as shown in the figure...
(Solved)
A uniform 120m metal rod is pivoted near one of its ends and kept in equilibrium by a spring balance as shown in the figure below.
The reading indicated by the spring balance is 2.0N. Work out the mass of the metal rod. (g = 10N/kg)
Date posted:
September 6, 2019
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Answers (1)
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The spiral springs shown in the figure below are identical. Each spring has a constant K = 300N/m.
Determine the extension caused by the 150N weight...
(Solved)
The spiral springs shown in the figure below are identical. Each spring has a constant K = 300N/m.
Determine the extension caused by the 150N weight (Ignore weight of springs and connecting rods)
Date posted:
September 6, 2019
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Answers (1)
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A micrometer screw gauge has a zero error of -0.02mm. It is used to measure the diameter of a wire. If the actual diameter of...
(Solved)
A micrometer screw gauge has a zero error of -0.02mm. It is used to measure the diameter of a wire. If the actual diameter of the wire is 0.28mm. Draw the micrometer screw gauge showing the diameter of the wire.
Date posted:
September 6, 2019
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Answers (1)
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A girl performed an experiment to measure the focal length of a converging mirror.In the experiment, a series of object distance,U(cm) and image distance V(cm)...
(Solved)
A girl performed an experiment to measure the focal length of a converging mirror.In the experiment, a series of object distance,U(cm) and image distance V(cm) were obtained and the graph UV cm2 against V+U obtained as shown below.
Use the graph to determine:
i) Focal length of the mirror.
ii) Radius of curvature.
iii) State two applications of diverging mirror.
iv) Explain how a concave mirror is used by a dentist to enlarge image of the tooth.
Date posted:
August 22, 2019
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Answers (1)
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The figure below shows a standing wave formed when a string of length 1.5 m stretched between two supports is plucked in the middle.
(Solved)
The figure below shows a standing wave formed when a string of length 1.5 m stretched between two supports is plucked in the middle.
(i) Explain how the standing wave is formed
(ii) Determine the wavelength of the standing wave
Date posted:
August 22, 2019
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Answers (1)
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The figure below shows crests of circular water waves spreading from two points A and B due to a vibrator. C and D are points...
(Solved)
The figure below shows crests of circular water waves spreading from two points A and B due to a vibrator. C and D are points on the surface of the water.
Given that the amplitude of each wave is 5 cm, state with a reason the amplitudes of the waves at point:
(i) C
(ii) D
Date posted:
August 22, 2019
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Answers (1)
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Sodium has a work function of 2.3eV. Given that: Planck’s constant h = 6.63 x 10-34JS, velocity of light in vacuum, C = 3.0 x108m/s,...
(Solved)
Sodium has a work function of 2.3eV. Given that: Planck’s constant h = 6.63 x 10-34JS, velocity of light in vacuum, C = 3.0 x108m/s, 1 electron-volt (1eV) = 1.6 x 10-19 C and mass of an electron, me = 9.1 x 10-31kg, calculate:
(i) Its threshold frequency.
(ii) The maximum velocity of the photoelectrons produced when the sodium is illuminated by light of wavelength 5.0 x 10-7m.
(iii) The stopping potential V, with the light of this wavelength.
Date posted:
August 22, 2019
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Answers (1)
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A G.M tube indicated a constant count rate of 5 counts per minute when a radioactive source was placed at a distance of about 10...
(Solved)
A G.M tube indicated a constant count rate of 5 counts per minute when a radioactive source was placed at a distance of about 10 cm from it. When the source was moved close to about 4cm the count rate varied as follows.
(i) The count rate was constant at a distance of 10 cm away. Explain
(ii) Plot a graph of count rate against time.
(iii) Use your graph to estimate the half-life of the radioactive source.
(iv) 
(v) State two precautions that have to be observed when using a radioactive substance.
(vi) Distinguish between fission and fusion.
Date posted:
August 22, 2019
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Answers (1)
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The figure below shows a circuit.
(Solved)
The figure below shows a circuit.
Calculate:
i) The total resistance of the circuit.
ii) The total current flowing in the circuit.
iii) The voltage drop across resistor R1.
iv) The current through the 3Ω resistor.
Date posted:
August 22, 2019
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Answers (1)
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The figure below shows a current carrying wire at right angle to a cardboard. Iron fillings are sprinkled on the card and card slightly tapped.
(Solved)
The figure below shows a current carrying wire at right angle to a cardboard. Iron fillings are sprinkled on the card and card slightly tapped.
Draw and indicate the direction of the magnetic field pattern displayed on the card.
Date posted:
August 22, 2019
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Answers (1)
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Explain the behavior of the pins as illustrated below
(Solved)
Explain the behavior of the pins as illustrated below
Date posted:
August 22, 2019
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Answers (1)
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A house has a lighting circuit operated from a 240V mains supply. Four bulbs rated 40W 240V and six bulbs rated 100W 240V are switched...
(Solved)
A house has a lighting circuit operated from a 240V mains supply. Four bulbs rated 40W 240V and six bulbs rated 100W 240V are switched on for 5 hours a day. Determine the monthly bill for the consumer given that the cost of electricity is at shs. 5.50 per unit.
(Take 1 month = 30 days and the standing charge is sh. 150)
Date posted:
August 22, 2019
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Answers (1)
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A girl standing at a distance claps her hands and hears an echo from a tall building 2 seconds later. If the speed of sound...
(Solved)
A girl standing at a distance claps her hands and hears an echo from a tall building 2 seconds later. If the speed of sound in air is 340m/s, determine how far the building is.
Date posted:
August 22, 2019
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Answers (1)