Q&A - P3 Science

[vlim]

PiggyLalala:

Need help. What is the definition of 'hard' in topic diversity ( material)? It is not the opposite of soft and hard is not equal to not fragile. Am i right to say that? Is wood considered as hard? Can give an example of hard object that is hard and not fragile other than diamonds. Hard : cannot be scratched easily???

metal ?...fragile is meant for glass right

[jedamum]

hardness is the ability to withstand scratches.

[jedamum]

PiggyLalala:

Need help. What is the definition of 'hard' in topic diversity ( material)? It is not the opposite of soft and hard is not equal to not fragile. Am i right to say that? Is wood considered as hard? Can give an example of hard object that is hard and not fragile other than diamonds. Hard : cannot be scratched easily???

piggylalala,
my boy is also having confusion over hard vs strong, fragile vs durable, elastic vs flexible.
whether wood is hard, have to have something to compare with.
hard objects can be glass. glass is hard, but brittle.

[PiggyLalala]

Metal can be scratched easily??? Yes / no?? So confusing...:(

[vlim]

PiggyLalala:

Metal can be scratched easily??? Yes / no?? So confusing...:(

but is hard right?..and strong...no?

[mdqs]

PiggyLalala:

Need help. What is the definition of 'hard' in topic diversity ( material)? It is not the opposite of soft and hard is not equal to not fragile. Am i right to say that? Is wood considered as hard? Can give an example of hard object that is hard and not fragile other than diamonds. Hard : cannot be scratched easily???

According to the science process skills book, a material is hard if it does not deform easily. It is also not easily scratched. Examples are metal and wood.

[jedamum]

PiggyLalala:

Metal can be scratched easily??? Yes / no?? So confusing...:(

haha...i think 'easily' or not, have to have something to compare with.
generally, metal, steel, concrete and some plastics are classify as 'hard' as they are not scratched easily.

[PiggyLalala]

jedamum:

PiggyLalala:

Need help. What is the definition of 'hard' in topic diversity ( material)? It is not the opposite of soft and hard is not equal to not fragile. Am i right to say that? Is wood considered as hard? Can give an example of hard object that is hard and not fragile other than diamonds. Hard : cannot be scratched easily???

piggylalala,
my boy is also having confusion over hard vs strong, fragile vs durable, elastic vs flexible.
whether wood is hard, have to have something to compare with.
hard objects can be glass. glass is hard, but brittle.

yupp.. same here.. so hard does not mean strong???

[jedamum]

PiggyLalala:

jedamum:

[quote=\"PiggyLalala\"]Need help. What is the definition of 'hard' in topic diversity ( material)? It is not the opposite of soft and hard is not equal to not fragile. Am i right to say that? Is wood considered as hard? Can give an example of hard object that is hard and not fragile other than diamonds. Hard : cannot be scratched easily???

piggylalala,
my boy is also having confusion over hard vs strong, fragile vs durable, elastic vs flexible.
whether wood is hard, have to have something to compare with.
hard objects can be glass. glass is hard, but brittle.

yupp.. same here.. so hard does not mean strong???[/quote]nonono...that is a common mistake.
Hard is the ability to withstand scratches.
Strong aka Strength is the ability to withstand load.
Glass is hard but not strong.

[PiggyLalala]

jedamum:

PiggyLalala:

[quote=\"jedamum] piggylalala,

my boy is also having confusion over hard vs strong, fragile vs durable, elastic vs flexible.
whether wood is hard, have to have something to compare with.
hard objects can be glass. glass is hard, but brittle.

yupp.. same here.. so hard does not mean strong???

nonono...that is a common mistake.
Hard is the ability to withstand scratches.
Strong aka Strength is the ability to withstand load.
Glass is hard but not strong.[/quote][/quote][/quote]

Thanks ...i know.. but can give examples of strong and hard object? metal?
stones considered as hard ???