I have the question "A body moves in a circle with a radius 450 km. The velocity at a point in the circle is 16 ms^-1. What is the acceleration of the body towards the circle at this point?"
So I know that the radius is 450000 metres and the velocity is 16 metres per second.
I do not know however which equation to use for the acceleration of the body towards the circle.
Centripetal acceleration for circular motion is $a_c=\frac{v^2}{r}$, where $v$ is the magnitude of the tangential velocity at any point on the circle, and $r$ is the radius of the circle. Note that the direction of the acceleration is always towards the center.