A small block of mass m m\,m is attached to a string and whirled in a horizontal circle of radius r r\,r on a frictionless tabletop. The linear speed of the block is vvv. The tension in the string is kept constant as the radius of the circle is varied.
Which relationship is correct for this system?
v∝1rv \propto \frac{1}{r}v∝r1
v∝r2v \propto r^2v∝r2
v∝rv \propto rv∝r
v2∝rv^2 \propto rv2∝r
