1. Rubber is elastic and when a nail is pushed through it, it stretches and grips the nail firmly without allowing air leakage
2.This is due to the valve effect i.e. pressure from inside causes the tyre rubber to press firmly on the nail, resulting to no air leakage
johnmulu answered the question on February 6, 2017 at 08:34
-
A solid weighs 16.5 N on the surface of the moon. The force of gravity on the moon is 1.7NKg-1. Determine the mass of the solid.
(Solved)
A solid weighs 16.5 N on the surface of the moon. The force of gravity on the moon is 1.7NKg-1. Determine the mass of the solid.
Date posted:
February 6, 2017
.
Answers (1)
-
A steel needle when placed carefully on water can be made to float. When a detergent is added to the water it sinks
(Solved)
A steel needle when placed carefully on water can be made to float. When a detergent is added to the water it sinks. Explain this observation
Date posted:
February 6, 2017
.
Answers (1)
-
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)
-
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)
-
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)
-
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)
-
A girl throws tennis ball vertically upwards from a truck moving at a constant velocity
(Solved)
A girl throws tennis ball vertically upwards from a truck moving at a constant velocity. Give the reason why the ball lands back exactly the same point where it was projected.
Date posted:
January 16, 2017
.
Answers (1)
-
When a steel ball bearing is dropped into a tall jar full of glycerine, it falls to reach a point when it attains a steady velocity
(Solved)
When a steel ball bearing is dropped into a tall jar full of glycerine, it falls to reach a point when it attains a steady velocity. State the force that varies to make this possible.
Date posted:
January 16, 2017
.
Answers (1)
-
Explain why milk in a bottle cools faster when the bottle is wrapped with wet towel
(Solved)
Milk in a bottle cools faster when the bottle is wrapped with a wet towel than when it is immersed in a bucket of cold water. Explain
Date posted:
January 16, 2017
.
Answers (1)
-
State samples of bromine vapour are allowed to diffuse separately under different conditions
(Solved)
State samples of bromine vapour are allowed to diffuse separately under different conditions; one in vacuum and the other in air. State and explain the observation made.
Date posted:
January 16, 2017
.
Answers (1)
-
Why is it easier to stop a saloon car than a bus moving at the same velocity?
(Solved)
It is easier to stop a saloon car than a bus moving at the same velocity. What is the reason?
Date posted:
January 14, 2017
.
Answers (1)