A model train, with a mass of #2 kg#, is moving on a circular track with a radius of #2/3 m#. If the train's rate of revolution changes from #1/2 Hz# to #6/5 Hz#, by how much will the centripetal force applied by the tracks change by?

1 Answer
Jan 1, 2018

The change in centripetal force is #=62.6N#

Explanation:

The centripetal force is

#F=(mv^2)/r=mromega^2N#

The mass of the train, #m=(2)kg#

The radius of the track, #r=(2/3)m#

The frequencies are

#f_1=(1/2)Hz#

#f_2=(6/5)Hz#

The variation in centripetal force is

#DeltaF=F_2-F_1#

#F_1=mromega_1^2=mr*(2pif_1)^2=2*2/3*(2pi*1/2)^2=13.2N#

#F_2=mromega_2^2=mr*(2pif_2)^2=2*2/3*(2pi*6/5)^2=75.8N#

#DeltaF=F_1-F_2=75.8-13.2=62.6N#