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X - rays travel in straight lines but cannot be focused by lenses.
Hence shadows formed by X-rays will have sharp edges only if they come from point source.
sharon kalunda answered the question on March 25, 2019 at 12:57
- State the energy changes that occur in the cathode ray tube.(Solved)
State the energy changes that occur in the cathode ray tube.
Date posted: March 25, 2019. Answers (1)
- Sketch a diagram of a simple cell.(Solved)
Sketch a diagram of a simple cell.
Date posted: March 25, 2019. Answers (1)
- The figure shows a device for closing a steam outlet
Determine the weight W that just holds the bar in the horizontal position shown.(Solved)
The figure shows a device for closing a steam outlet
The area of the piston is 4.0 x 10-4 m2 and the pressure of the steam in the boiler
is 2.0 x 105Nm-2. Determine the weight W that just holds the bar in the horizontal
position shown.
Date posted: March 25, 2019. Answers (1)
- A battery rated 80Ah. What does this mean?(Solved)
A battery rated 80Ah. What does this mean?
Date posted: March 25, 2019. Answers (1)
- A power line from a power sub-station to a town a few kilometres away has a resistance of 0.1 Ohm per kilometre. Determine the rate...(Solved)
A power line from a power sub-station to a town a few kilometres away has a resistance of 0.1 Ohm per kilometre. Determine the rate of energy loss is transmission of power over 50km at a current of 60 amperes.
Date posted: March 25, 2019. Answers (1)
- The figure below shows an arrangement for lighting three lamps, A, B and C only one of which is controlled directly by the switch.(Solved)
The figure below shows an arrangement for lighting three lamps, A, B and C only one of which is controlled directly by the switch.
a) Which of he lamp is directly controlled by the switch?
b) What is the name given to this use of an electromagnet?
c) Which lamps can be on at once?
d) Explain how lamp C comes in.
Date posted: March 25, 2019. Answers (1)
- In an experiment, the diameter, of the patch was measured to be 200mm for an oil drop of radius 0.25mm. Determine the diameter of the...(Solved)
In an experiment, the diameter, of the patch was measured to be 200mm for an oil drop of radius 0.25mm. Determine the diameter of the molecule of the oil.
Date posted: March 25, 2019. Answers (1)
- State one application of visible light.(Solved)
State one application of visible light.
Date posted: March 25, 2019. Answers (1)
- Arrange the following waves in order of decreasing wavelength.
Infrared, X-rays, microwaves, yellow light, radio waves, red light.(Solved)
Arrange the following waves in order of decreasing wavelength.
Infrared, X-rays, microwaves, yellow light, radio waves, red light.
Date posted: March 25, 2019. Answers (1)
- Two pins are hanging from a magnet as shown in the diagram below.(Solved)
Two pins are hanging from a magnet as shown in the diagram below.
Explain why they do not hang vertically downwards.
Date posted: March 25, 2019. Answers (1)
- The figure below shows a positive charge near a plate carrying negative charge.(Solved)
The figure below shows a positive charge near a plate carrying negative charge
Draw an electric field pattern between them
Date posted: March 25, 2019. Answers (1)
- A concave mirror produces a real image 2cm tall of an object 5.0mm tall placed 10cm from the mirror. Find the focal length of the...(Solved)
A concave mirror produces a real image 2cm tall of an object 5.0mm tall placed 10cm from the mirror. Find the focal length of the mirror.
Date posted: March 25, 2019. Answers (1)
- The figure below shows a ray of light incident to the first of the two mirrors placed at an angle of 60°.(Solved)
The figure below shows a ray of light incident to the first of the two mirrors placed at an angle of 60°.
Complete the part of the ray after reflection from the mirrors.
Date posted: March 25, 2019. Answers (1)
- A gas of volume 2m³ at 27°C is cooled to -123°C, at constant pressure. What is its new volume?(Solved)
A gas of volume 2m³ at 27°C is cooled to -123°C, at constant pressure. What is its new volume?
Date posted: March 25, 2019. Answers (1)
- A block of length 80cm, cross sectional area 3.0cm² and density 1300kg/m³ is completely immersed in a liquid of density 1030kg/m³. Determine
i) The mass of...(Solved)
A block of length 80cm, cross sectional area 3.0cm² and density 1300kg/m³ is completely immersed in a liquid of density 1030kg/m³. Determine
i) The mass of the block.
ii) The weight of the block in the liquid.
Date posted: March 25, 2019. Answers (1)
- A stone of mass 1.2 kg is tied to a rope and whirled in a vertical circle of radius 3.2m with a speed of 6.32m/s....(Solved)
A stone of mass 1.2 kg is tied to a rope and whirled in a vertical circle of radius 3.2m with a speed of 6.32m/s. Calculate
i) The centripetal acceleration of the stone.
ii) The tension in the rope when the stone is at the highest point.
Date posted: March 25, 2019. Answers (1)
- State two factors that affect centripetal force of a body moving a circular path(Solved)
State two factors that affect centripetal force of a body moving a circular path.
Date posted: March 25, 2019. Answers (1)
- The figure below shows the motion of a ticker tape through a ticker-timer whose frequency is 100Hz.(Solved)
The figure below shows the motion of a ticker tape through a ticker-timer whose frequency is 100Hz.
Determine:
I. Velocity at AB and PQ
II. Acceleration of the tape.
Date posted: March 25, 2019. Answers (1)
- The reading on a speedometer of a car of mass 1000 kg is 60 km/hr when the brakes are applied. The car is brought to rest...(Solved)
The reading on a speedometer of a car of mass 1000 kg is 60 km/hr when the brakes are applied. The car is brought to rest in 10 m.
Find
i) the retardation.
ii) find the average breaking force.
Date posted: March 25, 2019. Answers (1)
- In areas of the world where a plane is unable to land free fall airdrops can be used to deliver supplies. A plane travelling at...(Solved)
In areas of the world where a plane is unable to land free fall airdrops can be used to deliver supplies. A plane
i) Sketch the path followed by the falling load.
ii) Find the horizontal distance of the load from the drop zone to where it landed.travelling at a speed of 90m/s and a height of 100m releases a load of supplies.
Date posted: March 25, 2019. Answers (1)