# A model train with a mass of 6 kg is moving along a track at 8 (cm)/s. If the curvature of the track changes from a radius of 3 cm to 16 cm, by how much must the centripetal force applied by the tracks change?

$\setminus \Delta F = 1.04 N$
${F}_{\setminus} \circ = \frac{m {v}^{2}}{r}$
$\setminus \Delta F = {F}_{1} - {F}_{2} = \frac{m {v}^{2}}{r} _ 1 - \frac{m {v}^{2}}{r} _ 2 = \frac{6 \cdot {0.08}^{2}}{0.03} - \frac{6 \cdot {0.08}^{2}}{0.16} = 1.04 N$