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Types of forces: at a distance or through contact (4841)
Indicate which of these phenomena are produced by forces at a distance and which are produced by forces through contact:
a) The motion of a train due to magnetic levitation.
b) The deformation of a spring when a weight is attached to it.
c) The skidding of a car on a pool of water.
d) The formation of the aurora borealis.
e) The motion of a cupboard when pushed.
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Classifying into laws and theories
Classify the next examples as laws or theories, considering the definition of each one.
a) When the temperature rises, will be simpler to dissolve a solid into the water.
b) The global warming is due to the excessive emissions of carbon dioxide, and other gases, to the atmosphere and it is the cause of many changes in the climates of the Earth.
c) In a chemical reaction, the total mass of the initial substances is equal to the total mass of the final substances.
d) A chemical reaction implies that substances change their composition and they have to be converted from one to other different substances by the combination of their atoms.
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Classification of bodies: rigid, elastic or plastic (4842)
Classify the following objects into rigid, plastic or elastic bodies:
a) The mechanism of a key on the computer keyboard.
b) Sunglasses.
c) A headband.
d) A steel fork.
e) The bristles of a toothbrush.
f) Bread dough.
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Will do float silver over mercury?
Imagine that you heat a system with upper temperatures than the fusion points of silver and mercury. If you put in contact both substances, will do silver float over mercury? Look for the information that you need on the Internet and explain your answer.
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Volume occupied by a known mass of mercury
The density of mercury is 13.6 g/mL. What will be the volume of 25 000 g of mercury?
Bilingüismo
Ejercicios FyQ