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

1 Answer
Nov 22, 2017

Answer:

The change in centripetal force is #=44.4N#

Explanation:

The centripetal force is

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

The mass, #m=(3)kg#

The radius, #r=8m#

The frequencies are

#f_1=1/4=0.25Hz#

#f_2=1/8=0.125Hz#

The variation in centripetal force is

#DeltaF=F_2-F_1#

#F_1=mromega_1^2=mr*(2pif_1)^2=3*8*(2pi*0.25)^2=59.2N#

#F_2=mromega_2^2=mr*(2pif_2)^2=3*8*(2pi*0.125)^2=14.8N#

#DeltaF=F_1-F_2=59.2-14.8=44.4N#