Title Physics Lab Report Friction Acceleration Physical Sciences 471.6 KB 8
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DISCUSSION

In both experiments, the coefficient of static and kinetic friction µs and µ k. can be determined from the

gradient of the graph as each graph is and fk against R respectively.

Therefore, in part A, the coefficient of static friction, µs is :

fs = µs R

µs = fs/R

= y2 – y1
x2 – x1

= (0.70 - 0.48)
(3.08 - 2.29)

= 0.22/0.79

= 0.28

In part B, the coefficient of kinetic friction, µ k. is :

fk = µk R

µk = fk/R

= y2 – y1
x2 – x1

= (0.55 - 0.40)
(3.08 - 2.29)

= 0.15/0.79

= 0.19

Static friction is a force that acts to keep an object from moving. At rest, the value of force exerted (F)

is equal to the value of static friction force (fs). Therefore, when F increases, fs also increase.

Theoretically, the value of µs is greater than µk as it needs more force to move an object from rest. But,

when the object starts to move, less force is needed to maintain the motion. Due to this, in the first

experiment of static friction, no external force (push) is applied on the block. While on the second

experiment of kinetic friction, an external force (push) is applied every time the masses are added to

enable the block to move. This is because kinetic friction is the force that acts when the object is in

motion. This experiment can be said successful because the value of µs > µk. in which µs is 0.28 and µk is

0.19.