A model train, with a mass of $4 k g$ $4 kg$ , is moving on a circular track with a radius of $8 m$ $8 m$ . If the train's kinetic energy changes from $32 j$ $32 j$ to $0 j$ $0 j$ , by how much will the centripetal force applied by the tracks change by?

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Answer 1 · 2016-04-17T15:02:55

$8 N$ $8N$

Centripetal force is given as $F_{c} = \frac{m v^{2}}{r} = \frac{2 K.E.}{r}$ $F_c = (mv^2)/r = ("2 K.E.")/r$ .

Hence, $Delta F_c = (2 Delta"K.E.")/r = (2*(32-0) J)/(8m) = 8 N$

A model train, with a mass of 4 kg4kg4 kg, is moving on a circular track with a radius of 8 m8m8 m. If the train's kinetic energy changes from 32 j32j32 j to 0 j0j0 j, by how much will the centripetal force applied by the tracks change by?