Static Friction TLSAMP Summer Science Academy 2005

Group 3 Members Keshia Ashley Walter Ayla

Objective Our objective is to investigate the coefficient of the static friction for wood on wood.

Hypothesis There must exist some resistive force opposite to the direction of motion between two surfaces in contact. Mean Standard Deviation T-statistic Degree of Freedom 23 P-value

Materials  Wooden Block  Wooden Board  String  Weights  Balance  Pulley  Vice

Procedures 1)Place a wooden board on top of a table top surface 2)Attach the pulley and vice, then bind it to the table top and board 3)Use balance to weigh the block and find its mass.(Represented as ) 4)Tie a piece of string around the wooden block 5)Make sure the string is long enough to extend across the pulley and hold the weights over the edge of the table

Procedures (Cont.) 6)Position the wooden block about 12 inches away from the pulley 7)Begin to add weights to the opposite end of the string (the purpose of this is to add enough weight to move the wooden block across the wooden board, thus creating static friction.) 8)Record your results. 9)Add 100g weight on top of the wooden block and complete the previous 6-9.

Definitions/Formulas Mb=Mass of block Mw=Mass of Weight M=Mass Coefficient of static is the added together and divided by m. f F N F=mg F=f f= Mg=

Data

Data (Cont.)

Hypothesis Testing We failed to reject p-value = 0.43

Results According to our experiment the numerical coefficient of static friction is 0.35

Conclusion No matter how much weight we added to the wooden block, the coefficient of static friction was constant.