Mr Lau;

The mass of the object will change the amount of friction. If the object is heavier, greater pressure is acting on it, increasing the friction. But i think a better IV and DV would be the mass of the object and the load added to overcome the friction respectively.

Mr Lau;

Hmmm, i guess the IV would be the mass of the object.

Mr Lau;

Hey Mr Lau,
Thanks for your comments. :)
I got the idea from this source that i posted earlier: http://www.tribology-abc.com/abc/friction.htm

How to measure friction?

Method 1 Weight ratio The sketch shown originates from Leonardo da Vinci (ca 1500). He studied friction by measuring the load hanging on a cord, at which the block begins to slide. The coefficient of friction is found by the quotient of the dead weight of the mass hanging on the cord and the mass of the block, i.e.  µ =  Ff / N = mdead weight / mblock   Static coefficient of friction - dynamic coefficient of friction The moment at which the block begins to slide (break away force) is the so called static friction, the force at which the block continues to slide is the dynamic or kinetic coefficient of friction. For most material combinations the value of the static friction exceeds that of the dynamic friction. Be aware that the dynamic friction can still be dependent on velocity, contact pressure, temperature and surface roughness. The static friction can be dependent on the time that the block is in rest, which is typically the case when lubricated. I think we would be measuring static friction since once the load overcomes the opposing force, i presume the object would keep moving till it falls of the surface or the load hits the ground. Is that right? Oh, and can i ask this question? Why won't it score well? Is it better if i use only one fixed surface but change the mass if the object . In this case, our project would simulate the sport of Grand Prix where the fixed surface represents the racing track and the objects with different mass represents the different racing cars. Independent Variable: The object Dependent Variable: The static friction Can? :)

Drawings

Ok, here's the drawings. :)



Is it ok? :)

Well, i figured you can't really see what the scanned in picture wrote so i shall type it out instead. Sorry.
So, assuming that the object weighs 100g and surface 1, 2 and 3 are the least rough, rough and roughest surface respectively, then the experiment would look like the drawings above. As you can see, as the surface gets rougher, it takes a heavier weight to make the object move. So, if we record these information down on a table it would look like the one above.
Ratio=F/m

Mr Lau, is this better?

YOU HAVE TO CHECK THIS OUT.

Hey guys. :) Ok, so here's a summary of  a new idea i have for the project. :)

Firstly, the object will be kept constant while the surfaces used will vary through out the experiment. Secondly, to measure friction, we could use a pulley system and attach it to the object. We would have to keep adding weights to the pulley system till the object moves.

So, this should be our procedure:
Step 1. Chose 3 different surfaces (eg: parquet, concrete and terracotta tiles)
Step 2: Chose a flat object preferably less than a kg.
Step 3: Attach a pulley system to the object and make sure weights can be added onto it.
Step 4: Place the object onto the first surface (eg: parquet) and start adding weights until the object moves.
Step 5: Record the weights added.
Step 6: Repeat step 4 and 5 for the other 2 different surfaces.
Step 7: Plot a graph and table. :)

*The frictional force needed to overcome the mass of the object would be measured using the ratio of the weight added and the mass of the object. ---> Ratio: weight added/mass of object

So... For example, the object weighs 100g and for the test on parquet floor requires a 5g weight to be added, then the frictional force is 0.05N.

How does it sound? :)

How to post a comment

Haha, yes i don't know how to post a comment. I wrote a comment but can't post it even though i used a google account.

 Anyway, what i wanted to say is my science notebook is with you guys. :) its in the plastic bag with the blocks that i gave to hakim before i left. :) Please tell me its still with you. :)

How to measure friction.

Hey guys,
this might be helpful. :)
http://www.tribology-abc.com/abc/friction.htm

Mr Lau,

Um, because i thought that measuring friction would be tedious so i was looking for an alternative method to prove our hypothesis right. Also, i was unsure how to measure friction but i am still researching on it. Thank you for your comments. :)

Mr Lau,

Hey Mr Lau, do we have to measure the frictional force? Or can we change our hypothesis to: As the mass of the wooden block increases, it taked a longer time to travel the same distance. Therefore, it travels with a slower speed, which also means there is greater friction.

Re: Friction

The type of friction that is related to our experiment would be sliding friction (i.e: the force resulting when pushing or pulling an object over a surface). In this case, pulling the different weighted wooden blocks across the netball court would result in sliding friction. The link below tells us how to measure static sliding coefficient of friction with a ramp. It is a little complicated, though.  
http://www.school-for-champions.com/science/experiments/expfriction_static_coeff_ramp.htm

Friction

These are the 4 types of friction:
1. Static
2. Sliding
3. Rolling
4. Fluid
Static

• It is friction that acts on something that is not moving
• Eg: A piano is held in place by static friction
• Static friction keeps you in your seat
• No heat or wear is generated

Sliding

• It is a force resulting when pushing or pulling an object over a surface
• Eg: Pushing a box across the floor
• Heat and wear can result

Rolling

• Contact is reduced because of rollers or wheels or ball bearings
• Eg: Skate boards have ball bearings in the wheels
• Eg: A cart has wheels
• Less heat and wear will result in comparison with sliding.

Fluid

• Resistance from a liquid or air
• Eg: Stirring a thick batter
• Eg: Walking through water
• Eg: Olympic bike riders

Reducing friction
A smooth surface does demonstrate as much friction as a rough surface.
A lubricant can be used to reduce friction.

What is friction ? And how to measure it.

Friction is like the "evil" of all motions. No matter which direction something moves in, friction pulls it the other way. Move something left, friction pulls right. It is a force that appears whenever two things rub against each other.

How to measure friction ? Frictional force (Ff) is equal to the coefficient of friction (µ) multiplied by the normal force (Fn).

Definition of coefficient of friction --> The coefficient of friction is a number which represents the friction between two surfaces. Between two equal surfaces, the coefficient of friction will be the same. The symbol usually used for the coefficient of friction is (µ)

Definition of normal force -->
The force exerted by a surface on an object in contact with it which prevents the object from passing through the surface; the force is perpendicular to the surface, and is the only force that the surface exerts on the object in the absence of frictional forces.

However, i do not know how to measure this two things, any suggestions ?