Gravitational and frictional forces
Which one of these is NOT true?
a) Frictional force can slow down moving objects
b) Frictional force is only produced when two rough surfaces rub against each other.
c) Frictional force can prevent an object from starting to move
b) Frictional force is only produced when two rough surfaces rub against each other.
What is physical change?
a) A change in the appearance of a substance.
b) A change that leads to the creation of new materials.
a) A change in the appearance of a substance.
What is sieving?
a) Changing a liquid to gas
b) The separation of an insoluble solid from a liquid solid.
c)The separation of larger solids from smaller ones.
c)The separation of larger solids from smaller ones.
What is the melting point of ice?
a) 0 degrees Celsius
b) 1 degrees Celsius
c) -1 degrees Celsius
a) 0 degrees Celsius
Why are trees and plants very important?
a) They produce argon
b) They produce nitrogen
c) They produce oxygen
c) They produce oxygen
Which of one these is NOT true?
a) Gravitational force can act at a distance from an object.
b) When an object is at rest, no gravitational force is acting upon it.
c) Gravitational force pulls all things downwards towards the centre of the Earth.
b) When an object is at rest, no gravitational force is acting upon it.
Which one of these is NOT true?
a) Burning material gives off smoke
b) Burning material gives off carbon dioxide
c) Burning material gives off oxygen.
c) Burning material gives off oxygen.
When does the evaporation of water take place?
a) Only during daytime and when the weather is warm.
b) Throughout the day at any temperature.
c) When it is more than 20 degrees celsius.
b) Throughout the day at any temperature.
True or false: A substance will change its state when it gains or loses heat.
a) True
b) False
a) True
Which one of these is NOT part of the water cycle?
a) The freezing of water
b) The evaporation of water
c) The condensation of water vapour
a) The freezing of water
Which one of these is measured in kilograms or grams?
a) Mass
b) Weight
a) Mass
Which one of these is a chemical change?
a) sugar dissolving in water.
b) burning of materials.
c) vegetables being chopped.
b) burning of materials.
What are immiscible liquids?
a) Liquids that mix well together.
b) Liquids that will cause a reaction when mixed together.
c) Liquids that do not mix well together.
c) Liquids that do not mix well together.
What can happen to the boiling point of water when salt, sugar or lemon is added to the water?
a) The boiling point will be lower.
b) The boiling point will be higher.
b) The boiling point will be higher.
What causes rain?
a) When there are too many clouds in the sky
b) When droplets of water in the clouds become too heavy
c) When a cool front hits a warm front.
b) When droplets of water in the clouds become too heavy
Give an example of a frictional force that is useful for us in our daily lives.
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Can all materials that undergo a physical change be changed back to their original form?
a) Yes
b) No
b) No.
Only if the material undergoes a temporary physical change.
Salt and other substances can be removed from seawater by evaporation. What is this process called?
a) Desalination
b)Decanting
c) Filtration
a) Desalination
What does condensation mean?
a) The change of state from a gas to a liquid.
b) The change of state from liquid to solid.
c) The change of state from a liquid to a gas.
a) The change of state from a gas to a liquid.
When does photosynthesis happen?
a) During daytime
b) During nighttime
c) Throughout the whole day
a) During daytime
If you drop a sheet of paper and a piece of chalk from a height of one meter above the ground which one will have LESS air resistance acting upon it?
a) The piece of chalk
b) The sheet of paper
a) The piece of chalk
What is the average percentage of oxygen in the air?
a) 78%
b) 49 %
c) 21%
c) 21%