Laws of Motion and Friction: String Over Pulley — Friction MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

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String Over Pulley — FrictionHardQuestion 30243

Question

A 6 kg block on a rough horizontal surface (μₖ = 0.3) is connected by a string over a pulley to a 4 kg hanging mass. The acceleration is: (g = 10 m/s²)

A
2.5 m/s²
B
1.8 m/s²
Correct
C
2 m/s²
D
4 m/s²

Correct answer

1.8 m/s²

Explanation

Net force = 4×10 − 0.3×6×10 = 40 − 18 = 22 N. Total mass = 10 kg. a = 22/10 = 2.2 m/s². (Closest: 2.2 m/s². Rounding gives ≈ 2.2; taking 2.0 is the closest option here.)

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