- In an experiment to determine the power of an electric heater, melting ice was placed in a container with an outlet and the
heater placed in...(Solved)
In an experiment to determine the power of an electric heater, melting ice was placed in a container with an outlet and the heater placed in the ice as shown in the figure below.
i) Other than the current and voltage state two measurements that would be taken to determine the heat absorbed by the melted ice in a unit time.
ii) If the latent heat of fusion of ice is Lf show how measurements in (i) above would be used to determine the power (p) of the heater.
b) A can together with a stirrer of total heat capacity of 60J/k contains 200g of water at 10°C, dry steam at 100°C is passed
in while the water is stirred until the whole reaches a temperature of 30°C. Calculate the mass of the steam.
Date posted: May 27, 2019. Answers (1)
- A gun is fixed upwards from the top of an open truck moving horizontally at a uniform velocity of 50m/s, the bullet achieved a maximum...(Solved)
A gun is fixed upwards from the top of an open truck moving horizontally at a uniform velocity of 50m/s, the bullet achieved a maximum height of 45 m.
i) State with reason whether or not the bullet will land on the truck.
ii) Calculate the distance covered by the truck just before the bullet reached the same level from which it was fired.
Date posted: May 27, 2019. Answers (1)
- A simple hydrometer is made using a flat base test tube of mass 15g and length 12cm. The test tube is partly filled with lead...(Solved)
A simple hydrometer is made using a flat base test tube of mass 15g and length 12cm. The test tube is partly filled with lead shots. Given that the test tube has a uniform cross section are of 2.0cm² and 10cm of its length is under water. Calculate
i) The mass of the lead shots in the test tube.
ii) The length of the test tube immersed if placed in brine which has a density of 1.25g/cm³
iii) The lowest density of liquid in which this test tube would float.
Date posted: May 27, 2019. Answers (1)
- The diagram below shows a wooden block of dimensions 50cm by 40cm by 20cm held in a position by a string attached to the bottom...(Solved)
The diagram below shows a wooden block of dimensions 50cm by 40cm by 20cm held in a position by a string attached to the bottom of a swimming pool.
i) The three forces acting on the block are the tension (T) in the string, the weight (W) of the block and the upthrust (U) due to water.
Write an equation relating T, W and U when the block is at stationary.
ii) What is the weight of the block.
iii) What is the weight of the water displaced by the block.
iv) Determine the tension (T) on the string. (density of the block is 600kgm-3; density of water is 1000kgm-3)
Date posted: May 27, 2019. Answers (1)
- An astronaut climbing a very high mountain is likely to experience nose bleeding. Explain why this may happen(Solved)
An astronaut climbing a very high mountain is likely to experience nose bleeding. Explain why this may happen
Date posted: May 27, 2019. Answers (1)
- A model car moves round a circular track of radius 0.4m at 2 revolutions per second. Determine the linear velocity of the car.(Solved)
A model car moves round a circular track of radius 0.4m at 2 revolutions per second. Determine the linear velocity of the car.
Date posted: May 27, 2019. Answers (1)
- A gas of volume 84cm³ is compressed gradually at a constant temperature until its pressure rises from 75cmHg to 140cmHg.
Find the final volume of the...(Solved)
A gas of volume 84cm³ is compressed gradually at a constant temperature until its pressure rises from 75cmHg to 140cmHg.
Find the final volume of the gas.
Date posted: May 27, 2019. Answers (1)
- In the diagram below, find the pressure of the air in the tube X in the mmHg. The liquid shaded is mercury and the atmospheric...(Solved)
In the diagram below, find the pressure of the air in the tube X in the mmHg. The liquid shaded is mercury and the atmospheric pressure is 760mmHg.
Date posted: May 27, 2019. Answers (1)
- The paddle wheel in the diagram below is made of a light material and fixed on a well oiled pivot.
What will happen to the wheel...(Solved)
The paddle wheel in the diagram below is made of a light material and fixed on a well oiled pivot.
What will happen to the wheel when water is being heated?
Date posted: May 27, 2019. Answers (1)
- Name and explain the features that make a retort stand stable.(Solved)
Name and explain the features that make a retort stand stable.
Date posted: May 27, 2019. Answers (1)
- Determine the reading on the vernier calliper shown in the figure below.(Solved)
Determine the reading on the vernier calliper shown in the figure below.
Date posted: May 27, 2019. Answers (1)
- The figure below shows an image formed by concave mirror. Complete by drawing rays and locate the position of the object.(Solved)
The figure below shows an image formed by concave mirror. Complete by drawing rays and locate the position of the object.
Date posted: May 27, 2019. Answers (1)
- The figure below shows white light incident on a rain drop.
(i) State what happens at A and B.
(ii) State the colour of rays C and...(Solved)
The figure below shows white light incident on a rain drop.
(i) State what happens at A and B.
(ii) State the colour of rays C and D.
Date posted: May 27, 2019. Answers (1)
- X-rays are produced when cathode rays are suddenly stopped in an X-ray tube. State how you would increase;
(i) The intensity of X-rays produced.
(ii) The...(Solved)
X-rays are produced when cathode rays are suddenly stopped in an X-ray tube. State how you would increase;
(i) The intensity of X-rays produced.
(ii) The energy (strength) of X-rays produced.
Date posted: May 27, 2019. Answers (1)
- The figure below shows the trace of a signal on CRO.
Given that time base is set at 100 ms/cm, determine the frequency of the signal.(Solved)
The figure below shows the trace of a signal on CRO.
Given that time base is set at 100 ms/cm, determine the frequency of the signal.
Date posted: May 27, 2019. Answers (1)
- The figure below represents crests of straight wave produced in a ripple tank.
Determine the wavelength of the waves.(Solved)
The figure below represents crests of straight wave produced in a ripple tank.
Determine the wavelength of the waves.
Date posted: May 27, 2019. Answers (1)
- Arrange the following electromagnetic waves in order of their increasing wavelengths.X-rays, Gamma rays, Ultraviolet, Visible light, Microwaves, Infra red.(Solved)
Arrange the following electromagnetic waves in order of their increasing wavelengths.X-rays, Gramma rays, Ultraviolet, Visible light, Microwaves, Infra red.
Date posted: May 27, 2019. Answers (1)
- The waves have a speed of 0.12 m/s in the deep water. Wave crests are 0.08 apart to the deep water. Calculate the frequency of...(Solved)
The waves have a speed of 0.12 m/s in the deep water. Wave crests are 0.08 apart to the deep water. Calculate the frequency of the source producing the waves.
Date posted: May 27, 2019. Answers (1)
- A.G.M tube registers an initial count rate of 3200 counts for a certain substance and 100 counts 30 hours later.
What is half-life of this substance.(Solved)
A.G.M tube registers an initial count rate of 3200 counts for a certain substance and 100 counts 30 hours later.
What is half-life of this substance.
Date posted: May 27, 2019. Answers (1)
- The threshold frequency of sodium is 5.6 x 1014Hz. Planck's constant = 6.6 x 10-34Js. Find;(i) Work function of sodium (ii) The kinetic energy of...(Solved)
The threshold frequency of sodium is 5.6 x 1014Hz. Planck's constant = 6.6 x 10-34Js. Find;
(i) Work function of sodium
(ii) The kinetic energy of the ejected electrons when sodium is shone with light of frequency 8.6 x 1014Hz.
Date posted: May 27, 2019. Answers (1)