Different surfaces have different coefficient of friction. A smooth surface will have less friction than a rough surface. Static friction resists the initiation of motion while kinetic friction resist the motion of a moving object.
We observe this when we were adding gradually adding weights to the pan until it moved. The block did not move until we reach the maximum static frictional force the track can exert. Once the block moved, kinetic friction takes place. We found out the angle of repose is equal to the coefficient of friction. The value of the coefficient of friction we got in the first part and second part are exactly the same due to overused materials that can give us inaccurate result.
We can improve the results in the experiment by making sure that the materials used are in a good condition and following the procedure carefully. Friction can be used to our advantage. When we walk the static friction between our feet and the ground allows us to propel forward. Rather than our feet, simply, sliding back.
