Detergent lowers the surface tension of water making it stick to dirt and remove it. Penetrate the space between dirt and fabric.
Kavungya answered the question on October 1, 2019 at 10:40
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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 figure below shows part of a vernier caliper when the jaws are closed without an object between the jaws
(a) What is the value of...
(Solved)
The figure below shows part of a vernier caliper when the jaws are closed without an object between the jaws
(a) What is the value of the zero error of the callipers?
(b) A student used the same vernier calipers in (a) above to measure the diameter of a test tube whose actual diameter is 2.15cm. what was the reading shown by the calipers.
Date posted:
October 1, 2019
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Answers (1)
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To determine the relationship between angular velocity w and tension T, a student used a smooth disc with a hole at the centre, a string...
(Solved)
To determine the relationship between angular velocity w and tension T, a student used a smooth disc with a hole at the centre, a string and cylindrical object of mass m, as shown below
Describe how the student went about determining the relationship, specifying any other necessary material or instrument not shown in the diagram
Date posted:
October 1, 2019
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Answers (1)
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A bicycle wheel with radius 28cm moves with a linear velocity of 8m/s, determine
(Solved)
A bicycle wheel with radius 28cm moves with a linear velocity of 8m/s, determine
(i) the angular velocity of the wheel
(ii) the centripetal acceleration of a point on the rim of the wheel
Date posted:
October 1, 2019
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Answers (1)
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In an experiment, 100g of hot water at 90oC was mixed with 20g of ice at 0oC in a lagged plastics colorimeter.
(Solved)
In an experiment, 100g of hot water at 90oC was mixed with 20g of ice at 0oC in a lagged plastics colorimeter. After stirring, all the ice melted and the temperature of the mixture was found to be 61.5oC. Determine the latent heat of fusion of ice
(Specific heat capacity of water =4200Jkg-1k-1)
Date posted:
October 1, 2019
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Answers (1)
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A student set-up the apparatus as shown below to determine the power of an electric heater
(Solved)
A student set-up the apparatus as shown below to determine the power of an electric heater
(i) Other than time, state the measurements that would be used to determine the quantity of heat P absorbed by ice in a unit time
(ii) Complete the circuit to show the connection of the essential circuit components
(iii) Describe how the student would proceed to determine P
(iv) Give a reason why P may not be equal to the value indicated by the manufacturer
Date posted:
October 1, 2019
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Answers (1)
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The readings tabulated below shows how the length of a helical spring varied with the load hanging on it
(Solved)
The readings tabulated below shows how the length of a helical spring varied with the load hanging on it
(i) Complete the table to show the values of extension
(ii) Draw a graph of extension (y-axis) against load for the spring
(iii) Determining form the graph the proportionality constant of the spring
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 student holds a sheet of paper at an end so that it hangs in the position A as shown below
(Solved)
A student holds a sheet of paper at an end so that it hangs in the position A as shown below
Explain why the paper rises to the position B when the student blows air in the direction shown by the arrow
Date posted:
October 1, 2019
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Answers (1)
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The figure below shows a sheet of material with the shape of an isosceles triangle
(Solved)
The figure below shows a sheet of material with the shape of an isosceles triangle. Mark its centre of gravity accurately showing how you arrive at the answer
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 bob in the figure below is deflected then released to oscillate.
(Solved)
The bob in the figure below is deflected then released to oscillate. State and explain one factor that will determine whether the string breaks or not
Date posted:
October 1, 2019
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Answers (1)
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A single pendulum consisting of a heavy bob and string is suspended in air as shown in the figure below
(Solved)
A single pendulum consisting of a heavy bob and string is suspended in air as shown in the figure below
Mark on the diagram and name one other force acting on the bob
Date posted:
October 1, 2019
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Answers (1)
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An object weighs 2.6 N in air and 2.2 N when completely immersed in water. Determine the relative density of the object
(Solved)
An object weighs 2.6 N in air and 2.2 N when completely immersed in water. Determine the relative density of the object
Date posted:
October 1, 2019
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Answers (1)
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Complete the figure below to show how a single pulley can be arranged to a velocity ratio(V.R) of 2
(Solved)
Complete the figure below to show how a single pulley can be arranged to a velocity ratio(V.R) of 2
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)