MCQ
Two forces each numerically equal to $10$ $dynes$ are acting as shown in the adjoining figure, then the magnitude of resultant is.........$dyne$
- ✓$10$
- B$20$
- C$10\sqrt 3$
- D$5$
✓
Answer
Correct option: A.
$10$
a
Here, the angle $\theta$ between the two vectors is $120^{\circ}$
Here, the angle $\theta$ between the two vectors is $120^{\circ}$
$\begin{aligned} \therefore \mathrm{R} &=\sqrt{(10)^{2}+(10)^{2}+2(10)(10)\left(\cos 120^{\circ}\right)} \\ &=\sqrt{100+100-100}=10 \text { dyne } \end{aligned}$
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