A model train, with a mass of 3 kg3kg, is moving on a circular track with a radius of 8 m8m. If the train's rate of revolution changes from 1/4 Hz14Hz to 1/7 Hz17Hz, by how much will the centripetal force applied by the tracks change by?

1 Answer
Jul 23, 2018

The change in centripetal force is =39.88N=39.88N

Explanation:

The centripetal force is

F=(mv^2)/r=mromega^2NF=mv2r=mrω2N

The mass of the train, m=(3)kgm=(3)kg

The radius of the track, r=(8)mr=(8)m

The frequencies are

f_1=(1/4)Hzf1=(14)Hz

f_2=(1/7)Hzf2=(17)Hz

The angular velocity is omega=2pifω=2πf

The variation in centripetal force is

DeltaF=F_2-F_1

F_1=mromega_1^2=mr*(2pif_1)^2=3*8*(2pi*1/4)^2=59.22N

F_2=mromega_2^2=mr*(2pif_2)^2=3*8*(2pi*1/7)^2=19.34N

DeltaF=|F_2-F_1|=59.22-19.34=39.88N