Question

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. $v =4 \hat{ i } \,m / s , a =8 \hat{ j }\, m / s ^2$
• B. $v =4 \hat{ j } \,m / s , a =8 \hat{ i }\, m / s ^2$
• 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 1

Answer: (B)

$ a _{ c }=\frac{ V ^2}{ r }=\frac{4^2}{2}=\frac{16}{2}=8\,m / s ^2 $
$\vec{ V }=4 \hat{ j } $
$ \vec{a_c}=8 \hat{ i }$