Problem

Position vector (with respect to centre) velocity vector and acceleration vector of a particle in circular motion are

\mathbf{r} = (3\hat{i} - 4\hat{j})

\mathbf{v} = (4\hat{i} - a\hat{j})

ms^-1 and

\mathbf{a} = (-6\hat{i} + b\hat{j})

ms^-2. Speed of particle is constant. Match the following two columns.

Column I	Column II (SI units)
(a) Value of $a$	(p) 8
(b) Value of $b$	(q) 3
(c) Radius of circle	(r) 5
(d) $\mathbf{r} \cdot (\mathbf{v} \times \mathbf{a})$	(s) None