A block rests on a rough plane whose inclination θ is slowly increased from 0 to 90 ∘ . The frictional force on the block is m g sin θ before slipping begins and μ k m g cos θ after slipping begins.

Question

A block rests on a rough plane whose inclination θ is slowly increased from 0 to 90 ∘ . The frictional force on the block is m g sin θ before slipping begins and μ k ​ m g cos θ after slipping begins. The friction is maximum at: μ s ​ = 0.5 , μ k ​ = 0.4 .

TestHub · Accepted Answer

Static friction m g sin θ grows until slipping starts at tan θ = μ s ​ i.e. θ = tan − 1 ( 0.5 ) ≈ 26.6 ∘ after that the kinetic friction μ k ​ m g cos θ only decreases. The maximum is at θ = tan − 1 ( 0.5 ) . Option B.

Physics - NLM Question with Solution | TestHub

Options:

Doubts & Discussion