JEE Mains · Physics · STD 11 - 6. system of particles and rotational motion
A force of \(- P \hat{k}\) acts on the origin of the coordinate system. The torque about the point \((2,-3)\) is \(P(a \hat{i}+b \hat{j})\), the ratio of \(\frac{a}{b}\) is \(\frac{x}{2}\). The value of \(x\) is
- A \(1\)
- B \(2\)
- C \(3\)
- D \(4\)
Answer & Solution
Correct Answer
(C) \(3\)
Step-by-step Solution
Detailed explanation
\(\tau=\vec{r} \times \vec{F}\) \(\text { Where } \overrightarrow{ r }=-2 \hat{ i }+3 \hat{ j }\) \(\tau=(-2 \hat{ i }+3 \hat{ j }) \times(- Pk )\) \(= P (-2 \hat{ j }-3 \hat{ i })= P (-3 \hat{ i }-2 \hat{ j })\) \(\Rightarrow \text { So } a =-3, b =-2\)…
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