A body of mass $2 \mathrm{~kg}$ is acted upon by two forces each of magnitude $1 \mathrm{~N}$, making an…

A body of mass $2 \mathrm{~kg}$ is acted upon by two forces each of magnitude $1 \mathrm{~N}$, making an angle of $60^{\circ}$ with each other. The net acceleration of the body (in $\mathrm{ms}^{-2}$ ) is
  1. $0.5$
  2. $1.0$
  3. $\frac{\sqrt{3}}{2}$
  4. $\frac{\sqrt{2}}{3}$

Solution

Given that, mass of body, $m=2 \mathrm{~kg}$ Two forces $F_1$ and $F_2$ each of magnitude $1 \mathrm{~N}$ are acting on the body by making an angle $\theta=60^{\circ}$ with each other, then magnitude of resultant force by addition of two vectors is Net force, $F=\sqrt{F_1^2+F_2^2+2 F_1 F_2 \cos 60^{\circ}}$ Substituting the values, we get $F=\sqrt{(\mathrm{l})^2+(\mathrm{l})^2+2(\mathrm{l})(\mathrm{l}) \times \frac{\mathrm{l}}{2}}$ $=\sqrt{3} \mathrm{~N}$ By Newton's second law of motion, $F=m a$ $\therefore$ Acceleration of body, $a=\frac{F}{m}=\frac{\sqrt{3}}{2} \mathrm{~m} / \mathrm{s}^2$

Asked in: AP EAMCET 2021 (24 Aug Shift 2)

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