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4.1 , newtons laws of motion — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysics4.1 , newtons laws of motion1 Mark
MCQ
A block of mass $M$ placed inside a box descends vertically with acceleration $'a'$. The block exerts a force equal to one-fourth of its weight on the floor of the box. The value of $'a'$ will be .............
  • A
    $\frac{g}{4}$
  • B
    $\frac{g}{2}$
  • ✓
    $\frac{3 g }{4}$
  • D
    $g$
✓

Answer

Correct option: C.
$\frac{3 g }{4}$
c
$m g-N=m a$

$a=g-\frac{g}{4}$

$a=\frac{3 g}{4}$

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