#04 Static & Kinetic Friction

Semester 1 – #04 Static & Kinetic Friction

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Bin Contents: a case with cube materials, glass, ceramic or stone, rubber, small rod, 90-deg clamp, inclinometer, block with felt, supper pulley, and a 10-gram mass hanger.


Obtain a wooden plank and a stand – return when finished.


Connect the small rod to the stand via the 90-deg clamp as shown.


The wooden planks have a hole drilled through them; slide the small rod through that hole.


Take some masking tape and apply it to the plank.


Fold the tape onto itself as shown.


This will hold the inclinometer onto the wooden plank.

Note: As an alternative, you may use your drawer’s digital angle finder.


Weight the felt block’s mass.


A sample of the masses / objects used for Part A; take the brass masses from your drawer.


To perform Part A, set the object onto the wooden plank and raise the plank until you reach the maximum angle of repose, at which it will slide down the plank without acceleration.


As an alternative, set the object onto the wooden plank and hold it horizontally …


… then rotate the plank around the rod until you reach the maximum angle of repose.


For Parts B & C, set the wooden plank directly onto the table.


Attach the super pulley to the end of the wooden plank as shown.


A close up of the connection.


Obtain about 1 meter’s worth of the string (there is string at both sides of the lab).


Tie the string to the hook of the block and to the hanger.


Ensure that the string is always horizontal with respect to the wooden plank. Also the hanger should not swing.


Set load masses on top of the block and stack control masses onto the hanger until the block starts to move without acceleration.


We intend to use the wood on wood interface; so the felt should not make contact with the wooden plank.


For Part C, simply turn the block sideways; it’s exactly the same experiment as Part B.