Coefficient of Kinetic and Static Friction - Lab Report Example

1. The wooden block placed on the varnish material experienced the least coefficient of static friction. This is because the surface of the varnish material is smoother than the other materials. Therefore, it offers little resistance to motion i.e. for a given regular force, the force of friction is smaller on varnish material compared to other materials according to equation below;

 The varnish material still have the smallest coefficient of friction compared to wood and sandpaper.

2. The uncertainty coefficient of kinetic friction for the varnish material had the least amount of uncertainty. This is because its values were clustered very tightly and had the smallest standard deviation.
3. The coefficient of static friction for wood on wood obtained from the experiment was 0.3194. This value falls in the expected range of between 0.25 and 0.5 for wood on wood. For the kinetic friction, the coefficient obtained was 0.215.  This value compared to the expected 0.2 has a percentage difference of only 7.5%.
4. For objects inclined at an angle, the angle of inclination will be considered, and this will change the normal force to as in equation [1] below.

Where is the normal force,  is the gravitational force on the block and is the angle of inclination.

Therefore, the new set of equations will be;

Where  and are the coefficients of static and kinetic frictions respectively, and  and  are the static and kinetic friction.