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- In an experiment to determine the half-life of the radioactive element,the following data was obtained.(Solved)
In an experiment to determine the half-life of the radioactive element,the following data was obtained.
![q18b21020191143.png](/questions/uploads/q18b21020191143.png)
(i) Plot a decay curve for the element
(ii) Estimate from your graph the half-life of the element
Date posted: October 2, 2019. Answers (1)
- Use a suitable equation to show this decay(Solved)
Radon nuclide
decays to form polonium by emitting an alpha- particle use a suitable equation to show this decay
Date posted: October 2, 2019. Answers (1)
- Define background count(Solved)
Define background count
Date posted: October 2, 2019. Answers (1)
- 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.
![q1421020191135.png](/questions/uploads/q1421020191135.png)
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. Answers (1)
- Determine the amount of current passing through the 2O resistor shown in the figure below(Solved)
Determine the amount of current passing through the 2Ω resistor shown in the figure below
![q1121020191054.png](/questions/uploads/q1121020191054.png)
Date posted: October 2, 2019. Answers (1)
- The figure below shows two ways of biasing a P-N junction(Solved)
The figure below shows two ways of biasing a P-N junction
![q221020191050.png](/questions/uploads/q221020191050.png)
(i) In which circuit will current flow?
(ii) Explain your answer in (i) above.
Date posted: October 2, 2019. Answers (1)
- The energy of a radiation is 3.8 x10-14 J.(Solved)
The energy of a radiation is 3.8 x10-14 J. Determine the wavelength of the radiation
( h = 6.63x10-34JS,C=3.0 x 108m/s)
Date posted: October 2, 2019. Answers (1)
- Arrange the following radiations in order of increasing wavelength(Solved)
Arrange the following radiations in order of increasing wavelength; Ultra-violet, Microwaves, Blue light, Yellow light
Date posted: October 2, 2019. Answers (1)
- Figure below shows an object at the bottom of a water container. Draw rays on the diagram to show the object as viewed from above. (Solved)
Figure below shows an object at the bottom of a water container. Draw rays on the diagram to show the object as viewed from above.
![fig2811020191552.png](/questions/uploads/fig2811020191552.png)
Date posted: October 1, 2019. Answers (1)
- A girl looks into a plane mirror 3 m in front of her and sees the image of the wall which is 2.5 m behind her. What...(Solved)
A girl looks into a plane mirror 3 m in front of her and sees the image of the wall which is 2.5 m behind her. What is the difference between the girl’s eyes and the image of the wall?
Date posted: October 1, 2019. Answers (1)
- It is observed that when a magnet breaks up into two, each of the pieces retains the characteristics of the original magnet. Explain(Solved)
It is observed that when a magnet breaks up into two, each of the pieces retains the characteristics of the original magnet. Explain
Date posted: October 1, 2019. Answers (1)
- The figure below shows a bimetallic strip made of copper and iron at room temperature
If copper expands more than iron. Identify A and B if...(Solved)
The figure below shows a bimetallic strip made of copper and iron at room temperature
![fig2711020191434.png](/questions/uploads/fig2711020191434.png)
If copper expands more than iron. Identify A and B if the bimetallic strip is placed in a refrigerator whose temperature is -700c.
Date posted: October 1, 2019. Answers (1)
- The figure below shows how volume of a given mass of water varies with temperature.
sketch a graph of density against Temperature.(Solved)
The figure below shows how volume of a given mass of water varies with temperature.
![fig2511020191429.png](/questions/uploads/fig2511020191429.png)
sketch a graph of density against Temperature.
Date posted: October 1, 2019. Answers (1)
- 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.
![fig2311020191422.png](/questions/uploads/fig2311020191422.png)
(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. Answers (1)
- 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. Answers (1)
- 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.
![fig1911020191405.png](/questions/uploads/fig1911020191405.png)
(ii) Explain the difference between the two lines drawn
Date posted: October 1, 2019. Answers (1)
- The figure below shows a section of a tape from a ten tick timer whose frequency is 50 Hz.
Calculate;
(i) The average velocity of the...(Solved)
The figure below shows a section of a tape from a ten tick timer whose frequency is 50 Hz.
![fig1711020191400.png](/questions/uploads/fig1711020191400.png)
Calculate;
(i) The average velocity of the trolley between points
1. WX
2. YZ
(ii) Find the acceleration of the trolley.
Date posted: October 1, 2019. Answers (1)
- The velocity time graph in the figure below illustrates the motion of a ball which has been projected vertically upwards from the surface of...(Solved)
The velocity time graph in the figure below illustrates the motion of a ball which has been projected vertically upwards from the surface of a planet. The weight of the ball on earth is 30N
![fig1511020191351.png](/questions/uploads/fig1511020191351.png)
Determine the weight of a ball on the planet
Date posted: October 1, 2019. Answers (1)
- 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. Answers (1)
- 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. Answers (1)