Friction Lab

Project #525 on iSENSEProject.org

Purpose:  To investigate the relationship between the weight of an object on a flat surface surface and the static and kinetic frictional forces acting on the block as it is pulled.

Materials:  block and flat surface (each team to use a different combination of materials), string, spring scales, brass mass set

Procedure:

1. Select a pair of block-surface materials different for each team.

2. Tie a string on the block (to be used for pulling the block)

3. Measure the mass of the block in [kg]and calculate its weight in [N].Record your answers on the data table.

4. Add 200g (0.2 kg) of mass to the top of the block.Hook a spring scale to the spring and pull carefully, slowly increasing the force until JUST BEFORE the block moves.Do this a few times to see the highest pulling force.Record the highest pulling for (FFS = force (max)_ due to static friction) on the data table.

Note:  Make sure you are reading the N (newton) side of the scale, and be sure to choose the appropriate sized scale…it should stretch beyond the half-way point

1. Using the same mass, now gently and slowly pull the block across the surface at a slow, constant velocity.Do this a few times and and decide what average pulling force you are applying.Record the highest pulling for (FFK = force (max)f_ due to kineticfriction) on the data table.
    

2. Repeat steps 4 & 5, increasing the mass by 200g each time.You should end up with six data points.