A model train, with a mass of $4 kg$ , is moving on a circular track with a radius of $8 m$ . If the train's kinetic energy changes from $6 j$ to $15 j$ , by how much will the centripetal force applied by the tracks change by?

Question

1391 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-07-28T19:35:33

The change in centripetal force is $=2.25N$

The centripetal force is

$F=(mv^2)/r$

The kinetic energy is

$KE=1/2mv^2$

The variation of kinetic energy is

$Delta KE=1/2mv^2-1/2m u^2$

$=1/2m(v^2-u^2)$

The mass is $m=4kg$

The radius is $r=8m$

The variation of centripetal force is

$DeltaF=m/r(v^2-u^2)$

$DeltaF=2m/r1/2(v^2-u^2)$

$=(2)/r*1/2m(v^2-u^2)$

$=(2)/r*Delta KE$

$=2/8*(15-6)N$

$=2.25N$

A model train, with a mass of 4 kg4 kg, is moving on a circular track with a radius of 8 m8 m. If the train's kinetic energy changes from 6 j6 j to 15 j15 j, by how much will the centripetal force applied by the tracks change by?