Friction – Friend or Foe



aim-




To hypothesise and test what types of surface cause the most


friction.



hypothesis-

I presume that the roughest surface (eg. cement ) t will produce the most friction.

equipment-

-1x Newton Spring Balance -1x Block of Wood
-Different Surfaces [ e.g. ice, grass, dirt, etc. ]



independent


variables-


I will change the surfaces.



dependent


variables-




I will record what surface causes the most friction.



control


variables-




I will keep the spring balance, block of wood and the


Distance the block of wood will travel to ensure a fair


test.



method-




-First of all you will need all the Equipment listed


-Then take the block of wood and attach it to the spring balance


-Then you must drag the spring balance with the block of wood behind it


-Record the reading on the spring balance for each surface


-Repeat the dragging and recording process 3 times for each surface


-Then work out the average friction by adding all results for each surface and


dividing the answer by 3


-The surface with the highest average overall has produced the most friction



results-




Surface


Ice Cement Wood Grass Dirt


Trial 1 – 0.1 0.5 0.35 1.2 1.0


Trial 2 - 0.12 0.6 0.5 1.0 0.8


Trial 3 - 0.12 0.6 0.4 1.0 0.9


Average- 0.12 0.6 0.4 1.0 0.9



discussion-

SHAPE * MERGEFORMAT
1.0 Newtons-


0.9 Newtons-


0.8 Newtons-


0.7 Newtons-


0.6 Newtons-


0.5 Newtons-


0.4 Newtons-


0.3 Newtons-


0.2 Newtons-


0.1 Newtons-


0.0 Newtons-


Ice Cement Wood Grass Dirt


-What I hypothesized was that the cement would produce the most


friction. I was quite wrong, the grass actually produced the most


friction and not the cement.


-What I observed during my investigation did make sense according


my results. My results indicated that the most ‘uneven’ surface


produced the most friction and not the roughest as I guessed.


-Some surfaces [ the ice for example ] did not produce as much


friction [ as say the cement ] because it is a lot smoother. The


reason the grass produced the most friction was because the


surface was so uneven therefore it wasn’t easily pulled along the


distance.


-Some difficulties I experienced during my investigation were


inaccurate spring balances. They sometimes did not keep a


constant measure.


-If the school had newer spring balances then the readings would be


much more accurate then what they were. Also if the block of wood


had been carried a longer distance it would make for a more


accurate reading.



conclusion-




What I found was that the grass produced the most friction out of all of the surfaces that were tested. The reason grass produced more friction then any other was because of the surface being so uneven and bumpy which caused the person pulling the spring balance to apply more force. The more resistant the block of wood is the higher the Newton reading will be. This resulting in more friction.


10a