# A model train with a mass of 2 kg is moving along a track at 15 (cm)/s. If the curvature of the track changes from a radius of 5 cm to 12 cm, by how much must the centripetal force applied by the tracks change?

Change in force$= 52 , 500 \text{ }$Dynes

#### Explanation:

Force at radius ${r}_{1} = 5$

${F}_{1} = m {v}^{2} / {r}_{1} = 2000 {\left(15\right)}^{2} / 5 = 90000 \text{ }$Dynes

Force at radius ${r}_{2} = 12$

${F}_{2} = m {v}^{2} / {r}_{2} = 2000 {\left(15\right)}^{2} / 12 = 37500 \text{ }$Dynes

Change in force $= {F}_{1} - {F}_{2} = 90000 - 37500 = 52500 \text{ }$Dynes

God bless....I hope the explanation is useful.