MCQ
A particle initially at rest starts moving from reference point. $\mathrm{x}=0$ along $\mathrm{x}$-axis, with velocity $v$ that varies as $v=4 \sqrt{\mathrm{x} m} / \mathrm{s}$. The acceleration of the particle is __________$ \mathrm{ms}^{-2}$.
  • A
    $7$
  • $8$
  • C
    $9$
  • D
    $10$

Answer

Correct option: B.
$8$
b
$\mathrm{V}=4 \sqrt{\mathrm{x}}$

$\mathrm{a}=\mathrm{V} \frac{\mathrm{dv}}{\mathrm{dx}}$

$=4 \sqrt{\mathrm{x}} \times 4 \times \frac{1}{2} \mathrm{x}^{-1 / 2}=8 \mathrm{~m} / \mathrm{s}^2$

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