Physics · System Of Particles

JEE Main 2026 — 2 April, Evening Shift — Question 3

Two blocks of masses 2kg2\mathrm{kg} and 1kg1\mathrm{kg} respectively, are tied to the ends of a string which passes over a light frictionless pulley as shown in the figure below. The masses are held at rest at the same horizontal level and then released. The distance traversed by the centre of mass in 2s2\mathrm{s} is m\mathrm{m}. (Take g=10m/s2\mathrm{g} = 10\mathrm{m / s}^2)

Question figure
  1. Option A:

    0

  2. Option B:

    3.12

  3. Option C:

    2.22

    Correct
  4. Option D:

    1.42

Answer: C

Step-by-step solution

a=(2−1)3×10=103m/s2\mathrm{a} = \frac{(2-1)}{3}\times 10 = \frac{10}{3}\mathrm{m/s}^2, acm=1⋅10/3−2⋅10/33=−109m/s2\mathrm{a}_{\mathrm{cm}} = \frac{1\cdot10/3 - 2\cdot10/3}{3} = -\frac{10}{9}\mathrm{m/s}^2, Scm=12⋅109⋅4=209=2.22m\mathrm{S}_{\mathrm{cm}} = \frac{1}{2}\cdot\frac{10}{9}\cdot 4 = \frac{20}{9}=2.22\mathrm{m}

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Physics
Chapter
System Of Particles
Topic
Conservation of Linear Momentum
Two blocks of masses 2 kg and 1 kg respectively, are tied to the ends… | JEE Main 2026 PYQ with Solution · DhiX AI