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Question #42090

Difficulty: 8/10 | 🟢 Free

The Question

A wedge of angle θ=45∘\theta = 45^\circ is forced to accelerate horizontally to the right with a time-varying acceleration a(t)=kta(t) = kt (k>0k > 0). A small block of mass mm rests on its rough inclined surface. The coefficients of static and kinetic friction between the block and the wedge are μs=0.5\mu_s = 0.5 and μk=0.25\mu_k = 0.25, respectively. Assuming the wedge's acceleration remains continuous, what is the magnitude of the sudden change in the vertical acceleration of the block at the exact instant it begins to slip? (Let gg be the acceleration due to gravity)

Options

  • A.

    g4\frac{g}{4}

  • B.

    g2\frac{g}{2}

  • C.

    g2\frac{g}{\sqrt{2}}

  • D.

    gg

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Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Intuition_Breaker

Train your brain to resist "obvious" answers that are designed to deceive your intuition.

Concepts Behind This Question

Change in Velocity (Δv)|Wedge Constraint Logic|Static Friction Threshold|Vector Analysis

Why This Question Is Tricky

Common Mistakes

This question tests the dynamic constraint and the non-differentiable transition between static and kinetic friction regimes in a non-inertial frame.

Students often incorrectly assume that acceleration remains continuous or fail to properly resolve the relative acceleration vector into the ground frame.

The trap lies in missing the sudden drop in constraint force (friction) at the threshold, which induces an instantaneous jump in the block's absolute vertical acceleration, breaking the kinematic 'no-slip' constraint.

Quick Facts About This Question

Question Information

SubjectPhysics
ChapterMotion in a Plane - Class 11 Part 1
ConceptChange in Velocity (Δv)
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree