A model train, with a mass of #32 kg#, is moving on a circular track with a radius of #3 m#. If the train's kinetic energy changes from #18 j# to #21 j#, by how much will the centripetal force applied by the tracks change by?

1 Answer
Mar 4, 2018

Answer:

#2N#

Explanation:

suppose,initial velocity was #u# and then final velocity became #v#,so for a mass of #m#,we can say,its change in kinetic energy will be, #1/2 m(v^2-u^2)=21-18=3#

so, #m(v^2-u^2)=6......................1#

Now,change in centripetal force will be #m/r(v^2 - u^2)=6/r=6/3=2N# (from #1# and given, #r=3m#)