12V car battery has a very low internal resistance compared to high resistance (internal) of the eight dry cell. The car battery produces large currents which is able to start a car engine whereas 8 dry cell produce small currents which cannot start the engine.
Kavungya answered the question on October 3, 2019 at 06:02
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The diagram below represents an X –ray tube. The anode is made up of copper metal and tungsten as the target.
(Solved)
The diagram below represents an X –ray tube. The anode is made up of copper metal and tungsten as the target.
a) What are the functions of parts A and B.
b) Explain how X-rays are produced from the tube
c) Why is tungsten used for the target in the tube?
d) How can the quality of X-rays produced be controlled in the tube?
e) How can the quantity of the X-rays be increased?
Date posted:
October 2, 2019
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Answers (1)
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The following results were obtained in a experiment to verify Hooke’s law when a spring was extended by hanging various loads on it.
(I) Complete...
(Solved)
The following results were obtained in a experiment to verify Hooke’s law when a spring was extended by hanging various loads on it.
(I) Complete the table for the extension e above.
(II) Plot a graph of load (y-axis) against extension
(III) From the graph determine the springs constant
(IV) Calculate the energy stored when the spring is stretched to 16 cm.
Date posted:
October 1, 2019
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Answers (1)
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A stone of mass 5g is released from a catapult. The catapult is stretched by 10cm. If the constant of elasticity is 100N/cm. Calculate;
(i)...
(Solved)
A stone of mass 5g is released from a catapult. The catapult is stretched by 10cm. If the constant of elasticity is 100N/cm. Calculate;
(i) The horizontal velocity with which the stone is released
(ii) Sketch a graph of horizontal velocity against time from the time the stone is released to when it reaches the ground.
Date posted:
October 1, 2019
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Answers (1)
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The figure below shows the variation force with extension for a steel coil spring.
(i) On the same axes, sketch the variation of force with extension...
(Solved)
The figure below shows the variation force with extension for a steel coil spring.
(i) On the same axes, sketch the variation of force with extension for a wire form which the spring is made.
(ii) Explain the difference between the two lines drawn
Date posted:
October 1, 2019
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Answers (1)
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A modern car has a strengthened passenger cage but with front and back regions which can collapse in a crash. Explain how this collapsible...
(Solved)
A modern car has a strengthened passenger cage but with front and back regions which can collapse in a crash. Explain how this collapsible regions should reduce injury in a car crash.
Date posted:
October 1, 2019
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Answers (1)
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State one way of making surface tension of water stronger.
(Solved)
State one way of making surface tension of water stronger.
Date posted:
October 1, 2019
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Answers (1)
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Explain the washing effect of soap.
(Solved)
Explain the washing effect of soap.
Date posted:
October 1, 2019
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Answers (1)
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A bullet of mass 10g travelling at a speed of 400ms-1 hits a tree trunk, it penetrates the tree trunk and stops inside the trunk...
(Solved)
A bullet of mass 10g travelling at a speed of 400ms-1 hits a tree trunk, it penetrates the tree trunk and stops inside the trunk after 4 cm.
(a) Calculate the average resistance force offered by the trunk to the bullet.
(b) State the energy changes that takes place.
Date posted:
October 1, 2019
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Answers (1)
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Explain why a hole in a ship near the bottom is more dangerous than the one near the top
(Solved)
Explain why a hole in a ship near the bottom is more dangerous than the one near the top
Date posted:
October 1, 2019
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Answers (1)
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The figure below shows a pith ball being lifted into the funnel by blowing air into the funnel
Explain this observation
(Solved)
The figure below shows a pith ball being lifted into the funnel by blowing air into the funnel
Explain this observation
Date posted:
October 1, 2019
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Answers (1)
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A uniform metre rule of mass 40g is pivoted at the 60cm mark and held horizontally with a vertical string as shown below. Determine the...
(Solved)
A uniform metre rule of mass 40g is pivoted at the 60cm mark and held horizontally with a vertical string as shown below. Determine the tension in the string.
Date posted:
October 1, 2019
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Answers (1)
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The figure below shows a bimetallic wheel whose diameter is not affected by changes in temperature. Briefly explain how the diameter of the wheel remain...
(Solved)
The figure below shows a bimetallic wheel whose diameter is not affected by changes in temperature. Briefly explain how the diameter of the wheel remain unchanged as the temperature increases
Date posted:
October 1, 2019
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Answers (1)
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The diagram below shows two trolleys, A and B connected to each other by an elastic strip of negligible mass.
(Solved)
The diagram below shows two trolleys, A and B connected to each other by an elastic strip of negligible mass. The trolleys are pulled apart on a smooth plane till tension in the elastic strip is 4.0N and are then released suddenly
(a) State with reason the total momentum of the trolleys when they are just released
(b) Calculate the initial acceleration of trolley A when released
(c) The velocity of the trolley B is 0.9ms-1 just before it collides with A. Determine the velocity of A just before the collision
(d) Which trolley covers a longer distance before collision? Explain
(e) Explain why the elastic strip may not stretch to the same original length after impact
Date posted:
October 1, 2019
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Answers (1)
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A u-tube vertically holds two liquids L1 and L2 as shown in the figure below
(Solved)
A u-tube vertically holds two liquids L1 and L2 as shown in the figure below
(a) Mark accurately the point in liquid L2 that is at the same pressure as point P
(b) Determine the number of times L1 is denser than L2
Date posted:
October 1, 2019
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Answers (1)
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The figure below shows a path taken by a gas molecule moving from point x to z
(Solved)
The figure below shows a path taken by a gas molecule moving from point x to z
(a) Explain how this movement can be observed
(b) State in full, the law of motion that governs movement from x to z
Date posted:
October 1, 2019
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Answers (1)
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The machine represented in the diagram can be used to lift water from a well.
(Solved)
The machine represented in the diagram can be used to lift water from a well.
A force of 50N applied on the handle lifts water of weight 180N
i) Calculate the efficiency of the machine.
ii) Give a reason why the efficiency is less than 100%.
Date posted:
September 30, 2019
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Answers (1)
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A block of metal of mass 250g at 100°C is dropped into a lagged calorimeter of heat capacity 40J/K containing 100g of water at 25°C....
(Solved)
A block of metal of mass 250g at 100°C is dropped into a lagged calorimeter of heat capacity 40J/K containing 100g of water at 25°C. The temperature of the resulting mixture was found to be 40°C. Determine; (Cw = 4200J/k)
i) Heat gained by calorimeter.
ii) Heat gained by water.
iii) Heat lost by the block.
iv) Specific heat capacity of the metal block.
Date posted:
September 30, 2019
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Answers (1)
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In an experiment, it was observed that soapy water placed on a wet smooth surface displaced the particles of non-soapy water. Sate and explain this...
(Solved)
In an experiment, it was observed that soapy water placed on a wet smooth surface displaced the particles of non-soapy water. Sate and explain this observation.
Date posted:
September 30, 2019
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Answers (1)
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Give one reason why a lift pump raises water to heights less than 10m.
(Solved)
Give one reason why a lift pump raises water to heights less than 10m.
Date posted:
September 30, 2019
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Answers (1)
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A mass of 80kg is being lifted by a force F applied on the other piston of the machine as shown in the figure...
(Solved)
A mass of 80kg is being lifted by a force F applied on the other piston of the machine as shown in the figure below.Determine the value of F needed to just lift the 80kg mass given the density of the liquid is 1.2g/cm³.
Date posted:
September 30, 2019
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Answers (1)