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3.2 , motion in plane — Physics STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 SciencePhysics3.2 , motion in plane1 Mark
MCQ
An object moves at a constant speed along a circular path in a horizontal plane with centre at the origin. When the object is at $x =+2\,m$, its velocity is $-4 \hat{ j }\, m / s$. The object's velocity $(v)$ and acceleration $(a)$ at $x =-2\,m$ will be
  • A
    $v =4 \hat{ i }\,m / s , a =8 \hat{ j }\,m / s ^2$
  • ✓
    $v =4 \hat{ j }\,m / s , a =8 \hat{ i }\,m / s ^2$
  • C
    $v =-4 \hat{ j }\,m / s , a =8 \hat{ i }\,m / s ^2$
  • D
    $v =-4 \hat{ i }\,m / s , a =-8 \hat{ j }\,m / s ^2$
✓

Answer

Correct option: B.
$v =4 \hat{ j }\,m / s , a =8 \hat{ i }\,m / s ^2$
b
$a _{ c }=\frac{ V ^2}{ r }=\frac{4^2}{2}=\frac{16}{2}=8\,m / s ^2$

$\overrightarrow{ V }=4 \hat{ j }$

$\rightarrow a _{ c }=8 \hat{ i }$

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