Fractional drop in count rate
200 = 1/16 - ( ½ )4
3200
220 min = 4 half lives
? half life = 220 = 55 min
Lywascomputers answered the question on August 19, 2018 at 18:08
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A white paper is a good reflector of light but does not form an image like a mirror. Explain this observation
(Solved)
A white paper is a good reflector of light but does not form an image like a mirror. Explain this observation
Date posted:
August 19, 2018
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Answers (1)
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You are provided with the following apparatus. - a spring balance - a beaker - cork - a sinker - water
(Solved)
You are provided with the following apparatus.
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Date posted:
August 19, 2018
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Answers (1)
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Date posted:
August 14, 2018
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August 14, 2018
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Date posted:
August 7, 2018
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Date posted:
August 7, 2018
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Date posted:
August 7, 2018
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(Solved)
In an experiment to determine size of an oil molecule, 100 drops of oil of volume 1.54 cm cubic were run out of a pipette one drop was carefully placed on surface of water dusted with lycopodium powder and spread to form a uniform circular patch diameter 17.5
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3:size of oil molecule
Date posted:
August 7, 2018
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Answers (1)
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A garden sprinkler has 30 holes each of crossectional area 0.00006 square m and is connected to a hosepipe of ACS 0.0025 square m. If...
(Solved)
A garden sprinkler has 30 holes each of crossectional area 0.00006 square m and is connected to a hosepipe of ACS 0.0025 square m. If the speed of water in the hosepipe is 2m/s calculate the speed of water as it emerges from the holes
Date posted:
August 6, 2018
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Answers (1)
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A stone is dropped from the top of a tower 50m tall and another stone is projected vertically upwards at 40m/s at the same time....
(Solved)
A stone is dropped from the top of a tower 50m tall and another stone is projected vertically upwards at 40m/s at the same time. Determine the time taken for stones To meet.
Date posted:
August 6, 2018
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Answers (1)
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X-rays are used for detecting cracks inside metal beams.(i) State the type of the X-rays used(ii) Give a reason for your answer in (i) above.
(Solved)
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Date posted:
August 2, 2018
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Answers (1)
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A force of 100N is applied to an area of 100 square millimeters. What is the pressure exerted on the area?
Date posted:
July 20, 2018
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(Solved)
Distinguish between atomic structure and crystal structure.
Date posted:
July 13, 2018
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Answers (1)
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An immersion heater rated 240V, 10A is connected to a 250V mains supply. If it is used to heat 5kg of water at 20°, find...
(Solved)
An immersion heater rated 240V, 10A is connected to a 250V mains supply. If it is used to heat 5kg of water at 20°, find the temperature of the water after 7 minutes of heating. (3 marks)
Date posted:
July 11, 2018
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Answers (1)
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The term dipoles and domains are commonly used in magnetism. Distinguish between the two.
(Solved)
The term dipoles and domains are commonly used in magnetism. Distinguish between the two.
Date posted:
July 10, 2018
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Answers (1)
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Give the basic difference between direct current (D.C) generator and alternating current (A.C) generator.
(Solved)
Give the basic difference between direct current (D.C) generator and alternating current (A.C) generator.
Date posted:
July 9, 2018
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Answers (1)
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A light bulb is labelled 240V, 60W. Determine the resistance of the filament.
(Solved)
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Date posted:
July 8, 2018
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Answers (1)
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(Solved)
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Date posted:
July 5, 2018
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Answers (1)
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State the possible reason why if water is used as a barometer liquid, the glass tube required to hold the column of the liquid is...
(Solved)
State the possible reason why if water is used as a barometer liquid, the glass tube required to hold the column of the liquid is longer.
Date posted:
June 27, 2018
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Answers (1)
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The mass of the density bottle when filled with a liquid of density 3000 kg per metre cube is 400 grams and the mass of...
(Solved)
The mass of the density bottle when filled with a liquid of density 3000 kg per metre cube is 400 grams and the mass of the bottle when filled with water is 200 grams. What is the mass of the empty density bottle?
Date posted:
June 26, 2018
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Answers (1)