A model train, with a mass of #16 kg#, is moving on a circular track with a radius of #9 m#. If the train's kinetic energy changes from #40 j# to #9 j#, by how much will the centripetal force applied by the tracks change by?

1 Answer
Jul 12, 2017

Answer:

6.88 N.

Explanation:

Here,
In 1st case,

#KE =1/2 mv^2#
# 40*2 = mv^2#
#mv^2/r = 80/9#
#Fc = 80/9 N#

In 2nd case,

#m v^2/r = 2 * 9/9 = 2#
#Fc = 2 N#

#triangle Fc = 80/9- 2 = 62/9 = 6.88 N#

Thank you!!!