KVPY2010PhysicsLaws of Motion
A pen of mass ' m ^ is lying on a piece of paper of mass M placed on a rough table. If the coefficient of friction between the pen and paper, and, the paper and table are ₁ and ₂ , respectively, then the minimum horizontal force with which the paper has to be pulled for the pen to start slipping is given by-
Options
- A( m + M ) ( ₁+ ₂ ) g
- B( m ₁+ M ₂ ) g
- Cm ₁+(m+M) ₂ g
- Dm ( ₁+ ₂ ) g
Correct answer
A. ( m + M ) ( ₁+ ₂ ) g
Step-by-step solution
For pen to start slipping maximum horizontal force on it is f = mg a = ₁ ~g is the maximum common acceleration for both pen and paper F.B.D. for both pen and paper array l F = f ₁+ f ₂+ Ma F = ₁ mg + ₂( ~m + M ) g+ M ( ₁ ~g ) F =( m + M ) ( ₁+ ₂ ) g array