Question #2f246

1 Answer
Feb 22, 2017

Answer:

#36%#

Explanation:

Let the velocity be #=v#
Kinetic energy #=1/2mv^2=0.5mv^2#

The velocity is decreased by #20%#
#=># New velocity#=v-vxx20%=0.8v#
New Kinetic energy#=1/2m(0.8v)^2=0.32mv^2#

Decrease in kinetic energy#=0.5mv^2-0.32mv^2=0.18mv^2#
#%# Decrease in kinetic energy#=(0.18mv^2)/(0.5mv^2)xx100=36#