how would u measure the hardness of a surface? (1 Viewer)

[alias69]

how can u?

 

[mr_brightside]

In relation to what?
What subject is this in reference too?
What surface?

details

kthnxbye

 

[alias69]

well im doing a science experiment using the hypothesis ' the harder the surface the higher the bounce height of a ball will be' and the variable i am changing ( indepennt) is the surface...and i need to know how to measure the 'hardness'

 

[mr_brightside]

Well perhaps:

how easily it is scratched?
how hard it is to smash.
can scratch it with your fingernail?
can you break it with your hands.

Think about simple questions like this to describe the substance.
Perhaps rate each surface on a scale of one to ten from each question you ask about the surface, then take the average.

This will give you a scale of each "hardness" of the surfaces. Be sure to conclude HOW you can to this in your experiment

 

[Riviet]

Just an idea, but you could use a series of hitting objects like a hammer or crowbar to test the hardness of the surface. You start with a weak hitting object, then move onto the heavier/stronger objects if it doesn't break or crack.

 

[mr_brightside]

Just an idea, but you could use a series of hitting objects like a hammer or crowbar to test the hardness of the surface. You start with a weak hitting object, then move onto the heavier/stronger objects if it doesn't break or crack.

You wouldnt be able to control the force being applied though.

 

[Riviet]

Good point. I guess you could attempt to keep the force you apply as equal as possible. Otherwise, just scrap the idea as it won't be very reliable.

 

[felixcthecat]

what about applying a constant mass on the surfaces and measuring the indentation caused be the mass? although this would mean that the hardness of surfaces would have to vary quite significantly to measure any difference in hardness... not very scientific tho ^^''

 

[airie]

How about using Moh's Scale? I know it's more often used for minerals, but other substances can be tested using it too (we just did a prac yersterday in chem that involved this :mad1

Here are a few links explaining the Moh's Scale:
http://www.amfed.org/t_mohs.htm
http://www.answers.com/mohs+scale&r=67

Hope that helps

 

[vizman]

i think theres something called a Brinell Hardness Scale, you could try looking at that

 

[shinji]

wat bout the mass of the object in relation to its volume?

that'd tell the density of the object, thus the hardness ... coz .. the more density in a smaller volume which the object has, the harder it becomes ... or so i think! = ='

 

[stolenhotelpen]

to measure the hardness of a surface, use Moh's Scale of Hardness.
You compare your surface to the ones on the scale and then choose where it best fits in. Eg-a finger nail has a rating of 1 on the scale because it is as soft as Talc which is number one.
ill find a site to show you what it looks like..one sec
ill put it in next post

 

[stolenhotelpen]

http://www.minsocam.org/MSA/collectors_corner/article/mohs.htm

how this helps

tegan