Physics · Work, Power & Energy

JEE Main 2026 — 21 January, Evening Shift — Question 42

A body of mass 2 kg is moving along x -direction such that its displacement as function of time is given by x(t)=αt2+βt+γm\mathrm{x}(\mathrm{t})=\alpha \mathrm{t}^{2}+\beta \mathrm{t}+\gamma \mathrm{m}, where α=1 m/s2\alpha=1 \mathrm{~m} / \mathrm{s}^{2}, β=1 m/s\beta=1 \mathrm{~m} / \mathrm{s} and γ=1 m\gamma=1 \mathrm{~m}. The work done on the body during the time interval t=2 s\mathrm{t}=2 \mathrm{~s} to t=3 s\mathrm{t}=3 \mathrm{~s}, is ____\_\_\_\_ J.

  1. Option A:

    49

  2. Option B:

    42

  3. Option C:

    24

    Correct
  4. Option D:

    12

Answer: C

Step-by-step solution

x(t)=t2+t+1\mathrm{x}(\mathrm{t})=\mathrm{t}^{2}+\mathrm{t}+1 v(t)=2t+1\mathrm{v}(\mathrm{t})=2 \mathrm{t}+1 a(t)=2\mathrm{a}(\mathrm{t})=2 F=4 N\mathrm{F}=4 \mathrm{~N}. Displacement =x(3)−x(2)=\mathrm{x}(3)-\mathrm{x}(2) =13−7=6M=13-7=6 \mathrm{M} W=F.S=4×6=24 J\mathrm{W}=\mathrm{F} . \mathrm{S}=4 \times 6=24 \mathrm{~J}

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Physics
Chapter
Work, Power & Energy
Topic
Kinetic Energy and Work-Energy Theorem
A body of mass 2 kg is moving along x -direction such that its… | JEE Main 2026 PYQ with Solution · DhiX AI