The force of surface tension supports the needle on the surface but when the detergent is added, the surface tension reduces so the needle sinks.
johnmulu answered the question on February 6, 2017 at 08:26
- State two ways of reducing surface tension in water(Solved)
State ways of reducing surface tension in water.
Date posted: February 6, 2017. Answers (1)
- One factor that affect the surface tension of a liquid is the presence of impurities. State one other factor(Solved)
One factor that affect the surface tension of a liquid is the presence of impurities. State one other factor
Date posted: February 6, 2017. Answers (1)
- A bag of sugar is found to have the same weight on planet earth as an identical bag of dry sawdust on planet Jupiter(Solved)
A bag of sugar is found to have the same weight on planet earth as an identical bag of dry sawdust on planet Jupiter. Explain why the masses of the two bags must be different.
Date posted: February 6, 2017. Answers (1)
- A metal pin was observed to float on the surface of pure water. However the pin sank when a few drops of soap solution were carefully added to the water(Solved)
A metal pin was observed to float on the surface of pure water. However the pin sank when a few drops of soap solution were carefully added to the water. Explain this observation
Date posted: February 6, 2017. Answers (1)
- State the reason why water spilled on a glass surface wets the surface.(Solved)
State the reason why water spilled on a glass surface wets the surface.
Date posted: February 6, 2017. Answers (1)
- A butcher has a beam balance and masses 0.5 kg and 2 kg. How would he measure 1.5 kg of meat on the balance at once?(Solved)
A butcher has a beam balance and masses 0.5 kg and 2 kg. How would he measure 1.5 kg of meat on the balance at once?
Date posted: February 6, 2017. Answers (1)
- Why does the weight of the body vary from place to place?(Solved)
Give reason why the weight of the body varies from place to place.
Date posted: February 6, 2017. Answers (1)
- Name two forces that determine the shape of liquid drop on a solid surface.(Solved)
Name two forces that determine the shape of liquid drop on a solid surface.
Date posted: February 6, 2017. Answers (1)
- A student measured the length of a wire four times using a metre rule and obtained the following readings(Solved)
A student measured the length of a wire four times using a metre rule and obtained the following readings: 18.6 cm; 18.5 cm and 18.6 cm. Determine the length the length the student should record
Date posted: February 6, 2017. Answers (1)
- State the reason why it is not correct to quote the weight of solid objects in kilograms(Solved)
State the reason why it is not correct to quote the weight of solid objects in kilograms
Date posted: February 6, 2017. Answers (1)
- A stopwatch started 0.50s after the start button was pressed. The time recorded using the stopwatch for a ball bearing falling through a liquid was 2.53s.(Solved)
A stopwatch started 0.50s after the start button was pressed. The time recorded using the stopwatch for a ball bearing falling through a liquid was 2.53s. Determine the time of fall.
Date posted: February 6, 2017. Answers (1)
- A drug manufacturer gives the mass of the active ingredient in a tablet as 5 mg. Express this quantity in kilogramme and in standard form (Solved)
A drug manufacturer gives the mass of the active ingredient in a tablet as 5 mg. Express this quantity in kilogramme and in standard form.
Date posted: February 6, 2017. Answers (1)
- State what mechanics as a branch of physics deals with(Solved)
Mechanics is one of the branches of physics. State what it deals with.
Date posted: February 6, 2017. Answers (1)
- In which ways can the rate of evaporation of a liquid be increased?(Solved)
State two ways through which the rate of evaporation of a liquid may be increased.
Date posted: January 16, 2017. Answers (1)
- State Archimedes' principle(Solved)
State Archimedes' principle.
Date posted: January 16, 2017. Answers (1)
- State the pressure law for an ideal gas(Solved)
State the pressure law for an ideal gas.
Date posted: January 16, 2017. Answers (1)
- Why is it not advisable to melt ice directly using an electric heating coil?(Solved)
Give a reason why it is not advisable to melt ice directly using an electric heating coil.
Date posted: January 16, 2017. Answers (1)
- Define specific latent heat of vaporization(Solved)
Define specific latent heat of vaporization.
Date posted: January 16, 2017. Answers (1)
- Why should a safety belt used in a vehicle have a wide surface area and be slightly extensible?(Solved)
Give reasons why a safety seat belt used in a vehicle;should have a wide surface area and should be slightly extensible.
Date posted: January 16, 2017. Answers (1)
- Define impulse in terms of momentum(Solved)
Define impulse in terms of momentum
Date posted: January 16, 2017. Answers (1)