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Static friction is the resistive force perceived in a body that is at rest. It is articulated as

Where,

• static friction is F_s
• the coefficient of static friction is μ_s
• the normal force is F_n

Static Friction Formula helps one to compute the frictional force, coefficient of friction, or normal force in any asked numerical.

Static Friction Solved Examples

Underneath are numerical on static friction which helps to comprehend where one can use this formula:

Problem 1: A force of 200 N is exerted on a snack box of 5 kg still on the floor. If the coefficient of friction is 0.3, calculate the static friction.
Answer:

Known:

Fn (Normal force) = 200 N,
μ_s  (Coefficient of friction) = 0.3,
Static friction is given by F_s =μ_s  F_n
= 0.3 × 200 N
F_s = 60 N.

Problem 2: Amy is hauling a toy car of mass 4 kg which was at rest earlier on the floor. If 50 N is the value of the static frictional force, calculate the friction coefficient?
Answer:

Known:

m (Mass) = 4 kg,
F_s  (static frictional force) = 50 N,
F_n (Normal force) = mg
= 4 Kg × 9.8 m/s²
F_n= 39 N

μ_s = F_s /F_n

μ_{s =} 50/39

μ_{s  =} 1.282