Motion in a Plane - Result Question 19

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21. A body constrained to move in $y$-direction, is subjected to a force given by $\vec{F}=(-2 \hat{i}+15 \hat{j}+6 \hat{k}) N$. What is the workdone by this force in moving the body through a distance of $10 m$ along $y$-axis?

======= ####21. A body constrained to move in $y$-direction, is subjected to a force given by $\vec{F}=(-2 \hat{i}+15 \hat{j}+6 \hat{k}) N$. What is the workdone by this force in moving the body through a distance of $10 m$ along $y$-axis?

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/motion-in-a-plane/motion-in-a-plane—result-question-19.md (a) $190 J$

(b) $160 J$

(c) $150 J$

(d) $20 J$

[1994]

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Solution:

  1. (c) Since displacement is along the $y$-direction, hence displacement $\vec{s}=10 \hat{j}$.

Work done $=\vec{F} \cdot \vec{s}$

$=(-2 \hat{i}+15 \hat{j}+6 \hat{k}) \cdot 10 \hat{j}=150 J$