For a particle in uniform circular motion the acceleration $\vec { a }$ at a point $P ( R , \theta )$ on the circle of radius R is (here $\theta$ is measured from the $x$-axis) (1) $- \frac { v ^ { 2 } } { R } \cos \theta \hat { i } + \frac { v ^ { 2 } } { R } \sin \theta \hat { j }$ (2) $- \frac { v ^ { 2 } } { R } \sin \theta \hat { i } + \frac { v ^ { 2 } } { R } \cos \theta \hat { j }$ (3) $- \frac { v ^ { 2 } } { R } \cos \theta \hat { i } - \frac { v ^ { 2 } } { R } \sin \theta \hat { j }$ (4) $\frac { v ^ { 2 } } { R } \hat { i } + \frac { v ^ { 2 } } { R } \hat { j }$
For a particle in uniform circular motion the acceleration $\vec { a }$ at a point $P ( R , \theta )$ on the circle of radius R is (here $\theta$ is measured from the $x$-axis)\\
(1) $- \frac { v ^ { 2 } } { R } \cos \theta \hat { i } + \frac { v ^ { 2 } } { R } \sin \theta \hat { j }$\\
(2) $- \frac { v ^ { 2 } } { R } \sin \theta \hat { i } + \frac { v ^ { 2 } } { R } \cos \theta \hat { j }$\\
(3) $- \frac { v ^ { 2 } } { R } \cos \theta \hat { i } - \frac { v ^ { 2 } } { R } \sin \theta \hat { j }$\\
(4) $\frac { v ^ { 2 } } { R } \hat { i } + \frac { v ^ { 2 } } { R } \hat { j }$